Give the reference as soon as you've mentioned in your article the idea or fact you're using, not just at the end of the paragraph. It's often recommended to name the authors ("X says" and "Y argues against X,") and then indicate your own stand ("A more inclusive perspective, however, . . . ").
You need to keep mentioning authors, pages, dates to show how your ideas are related to those of the experts. You need to identify the source every time, and that applies to Internet sources too. When using any information from Internet you need author and date as well as title and URL.
Be sure to name sources even when you are not using the exact original words. It's often a good idea to mention the author's name. There are many different ways to identify the source in scientific articles. See the examples below.
As Morris puts it in The Human Zoo (1983), "we can always be sure that today's daring innovation will be tomorrow's respectability" (p. 189).
Al-Widyan and Al-Shyoukh  conducted an experimental investigation of the transesterification of waste palm oil into biodiesel fuel.
Van den Berghe et al [8,9] showed that tight glucose control (TGC) reduced intensive care unit (ICU) patient mortality up to 45% using a target of 6.1 mmol/L. Other studies with similar or slightly higher targets have successfully reduced mortality [10,11].
Northrop Frye discusses comedy in terms of the spring spirit, which he defines as the infusion of new life and hope into human awareness of universal problems (Anatomy 163).
The effect was so considerable that “the noise of the cannons in 1894 shattered into pieces the nice dreams of the numerous ministers from the School of Foreign Affairs and also acutely shocked the age-old heart of the Chinese people”(Gao, et al 1992: 5).
As G. Toury suggests, “most texts were selected for ideological reasons” (cited in Gentzler 1993: 126).
In Krathwohl's (1994) terms Bloom provided us with a set of heuristics. According to Krathwohl, “heuristic frameworks are valued for the thought they stimulate, often leading to new insights and understanding” (p. 182).
If you use the author's exact words, enclose them in quotation marks, or indent passages of more than four lines. Try to quote only when the original words are especially memorable. In most cases, use your own words to paraphrase and summarize the idea or results you want to discuss.
To paraphrase means to express someone else's ideas in your own language. To summarize means to distill only the most essential points of someone else's work. When you paraphrase, please remember these two points that you must provide a reference. The paraphrase must be entirely in your own words, and so you should completely alter the sentence structure.
Read and paraphrase the following statements. Please be sure to identify the source.
1. Psychotherapy explores a person's life to bring forth possible contributing causes of depression. During treatment, the therapist helps the patient to become aware of his or her thinking patterns and how they originated.
(Source: Belinda Rowland, Teresa G. Odle. Depression. Gale Encyclopedia of Alternative Medicine. The Gale Group Inc., Gale, Detroit, 2005).
2. One of the interesting design parameters which influence the efficiency of the steam system as well total requirements on make-up and condensate preheating is the rate of condensate returned to the boiler house.
(Source: Martin Pavlas, Petr Stehlík, Jaroslav Oral, Jirí Klemešc, Jin-Kuk Kim, Barry Firth. Heat integrated heat pumping for biomass gasification processing. Applied Thermal Engineering 30 (2010) 30–35).
3. No single set of guidelines could do justice to the many factors that impact on children’s play, even if it was to focus only on children living in the United States.
(Source: Kenneth R. Ginsburg. The Importance of Play in Promoting Healthy Child Development and Maintaining Strong Parent-Child Bonds. American Academy of Pediatrics Report, October 9, 2006).
When you summarize a passage, you need first to absorb the meaning of the passage and then to express in your own words the most important elements from the original passage. A summary is usually shorter than a paraphrase.
Summarize the information from the following paragraphs. Please be sure to identify the source correctly.
1. The conventional view of the research process is that we first derive a set of hypotheses from a theory, design and conduct a study to test these hypotheses, analyze the data to see if they were confirmed or disconfirmed, and then chronicle this sequence of events in the journal article. If this is how our enterprise actually proceeded, we could write most of the article before we collected the data. We could write the introduction and method sections completely, prepare the results section in skeleton form, leaving spaces to be filled in by the specific numerical results, and have two possible discussion sections ready to go, one for positive results, the other for negative results
(Source: Darley, J. M., Zanna, M. P., & Roediger III, H. L. (Eds). Writing the Empirical Journal Article (2003). The Compleat Academic: A Practical Guide for the Beginning Social Scientist, 2nd Edition. Washington, DC: American Psychological Association).
2. Since the char gasification process is the rate limiting step, it is important to quantify the kinetic parameters of char gasification. Char gasification has been investigated by a large number of researchers. Some of the important parameters investigated include the origin of the char sample, gasifying agent, total pressure, variation of partial pressure of gasifying agents, geometric changes of the sample during gasification, and catalyzed char gasification. One of the most important parameters which have been investigated is the catalytic effect of ash content on char gasification.
Catalytic effect of ash on char gasification has been investigated for several biomass samples. Kinetics of food waste char gasification did not draw the attention of researchers in this field. Since food waste has considerable ash content, its catalytic effect must be investigated. Results show that ash has a positive effect on char reactivity. Kinetic parameters have been calculated for different degrees of conversion. Values of kinetic parameters were found to be affected by the degree of conversion. Quantitative analysis of kinetic parameters dependency on sample conversion has been examined here. Quantifying the catalytic effect of ash on char kinetics will help assist improving gasifiers design with better controlled parameters for input and operational conditions, such as, operating temperature, gasification condition, gasifying support media, rate of feedstock to the gasifier. In conjunction with fluid dynamic simulations, improved expressions for reaction rates will help provide better estimate on char particles residence time in the reactor by providing an accurate conversion-time relationship.
Consequently, for a desired feed rate of feedstock into the reactor and for known gasifier operational conditions an accurate reactivity expression will lead to a close estimate of the gasifier size and configuration. If a constant reactivity value is used in reacting flow simulations for feedstock having time dependant reactivity, misleading information on char particles residence time will be obtained.
(Source: I.I. Ahmed, A.K. Gupta. Pyrolysis and gasification of food waste: Syngas characteristics and char gasification kinetics. Applied Energy 87 (2010) 101–108)
3. There is a definite need to develop a surgical robot which is more compact and less expensive than existing systems. Our goal is to enhance and improve surgical procedures by placing small, mobile, multi-function platforms inside the body that can begin to assume some of the tasks associated with surgery. We want to create a feedback loop between new, insertable sensor technology and effectors we are developing, with both surgeons and computers in the information-processing/control loop. We envision surgery in the future as radically different from today. This is clearly a trend that has been well-established as minimal-access surgical procedures continue to expand. Accompanying this expansion have been new thrusts in computer and robotic technologies that make automated surgery, if not feasible, an approachable goal. It is not difficult to foresee teams of insertable robots performing surgical tasks inside the body under both surgeon and computer control. The benefits of such an approach are well documented: greater precision, less trauma to the patient, and improved outcomes. One factor limiting this expansion is that the laparoscopic paradigm of pushing long sticks into small openings is still the state-of-the-art, even among surgical robots such as DaVinci. While this paradigm has been enormously successful, and has spurred development of new methods and devices, it is ultimately limiting in what it can achieve. Our intent is to go beyond this paradigm, and remotize sensors and effectors into the body cavity where they can perform surgical and imaging tasks unfettered by traditional endoscopic instrument design.
(Source: Tie Hu et al. Insertable Surgical Imaging Device with Pan, Tilt, Zoom, and Lighting. International Journal of Robotics Research, 175(6):482-487, 1998).
List of Works cited
At the end of your article you should list all literature cited in your paper, in alphabetical order, by first author. In a proper research paper, only primary literature is used (original research articles authored by the original investigators).
Please see the examples below.
Aikin, W. (1942). Adventure in American education, Vol. 1: Story of the Eight Year Study. New York: Harper & Brothers.
Anderson, L. W. (1985). A retrospective and prospective view of Bloom's “learning for mastery.” In M. C. Wang & H. J. Walberg (Eds.), Adapting instruction to individual differences. Berkeley, CA: McCutchan.
Anderson, L. W. (1994). Research on teaching and teacher education. In L. W. Anderson & L. A. Sosniak (Eds.). (1994). Bloom's taxonomy: A forty-year retrospective. Chicago: University of Chicago Press.
Anderson, L. W. (1996a). Benjamin Bloom, values and the professoriate. In C. Kridel, R. V. Bullough, Jr., & P. Shaker (Eds.), Teachers andmentors: Profiles of distinguished twentieth-century professors of education (pp. 45–54). New York: Garland.
Amelung, Iwo, Michael Lackner & Joachim Kurtz (2001). “Introduction”. In Michael Lackner, Iwo Amelung and Joachim Kurtz (eds.). New Terms for New Ideas: Western Knowledge and Lexical Change in Late Imperial China. Leiden: Brill, 1-12.
Li, Xinghua (ed.) (1997). Minguo jiaoyushi (The History of Education of the Republic of China). Shanghai: Shanghai Education Press.
Métailié, Georges (2001). “The Formation of Botanical Terminology: A Model or a Case Study?” In Michael Lackner, et al (ed), New Terms for New Ideas: Western Knowledge and Lexical Change in Late Imperial China. Leiden: Brill, 327-338.
Montgomery, Scott L. (2000). Science in translation: Movements of knowledge through cultures and time. Chicago: University of Chicago Press.
 T. Markvartand, C. Luis, Practical Handbook of Photovoltaics: Fundamentals and Applications. Elsevier, Oxford, 2003, pp. 367–413.
 M. Bar,W. Bohne, J.Rohrich, E.Strub, S. Lindner, M.C. Lux-Steiner, Ch.-H. Fischer, Determination of the bandgap depth profile of the penternary Cu(In(1_x)Ga(x))(SySe(1_y))2 chalcopyrite from its compositional gradient, J. Appl.Phys.96(2004)3857–3860.
 M.A. Green, Third Generation Photovoltaics: Advanced Solar Energy Conversion, Springer,Berlin,2003,pp59–67.
 B. Marsen, S. Dorn, B. Cole, R.E. Rocheleau, E.L. Miller, Copper chalcopyrite film photocathodes for direct solar-powered water splitting, Mater.Res.Soc.Symp. Proc. 974(2007)0974-CC09-05.
 E. Miller, E. Paluselli, B. Marsen, R. Rocheleau, Optimization of hybrid photoelectrodes for solar water splitting, Electrochem. Solid-State Lett.8 (2005) A247–A249.
 B. Marsen, B. Cole, S. Dorn, R.E. Rocheleau, E.L. Miller, Coppergallium diselenide photocathodes for solar-photoelectrolysis, Proc.SPIE6650(2007) 665006.
 J. Rifkin, The Hydrogen Economy: The Creation of the Worldwide Energy Web and the Redistribution of Power on Earth, J.P. Tarcher/Putnam, NewYork, 2003.
Make a List of Works (Bibliography) you are going to cite in your article.
IV. Writing the draft
Writing an Introduction
Introduction is an obligatory part that precedes the main body of your article. The Introduction introduces the reader to the topic or subject. The author should not plunge unprepared readers into the middle of the discussed problem or theory. We need to take some time and space necessary to lead them up to the formal or theoretical statement of the problem step by step.
Consequently, it is necessary to arrange the information from general to more specific. It is also recommended to give a reader a historical context so that they can understand the significance of your article. It is necessary to use examples to illustrate theoretical points or to introduce unfamiliar conceptual or technical terms. The more abstract the material, the more important examples become.
Dumping food waste in a landfill causes environmental problems. By volume, the dumped landfill waste causes the largest contribution to methane gas production . It causes odor as it decomposes to cause public annoyance in addition to forming germs, and attracting flies and vermin. Another serious problem of food wastes is the generation of landfill leachate. Landfill leachate is liquid that leaks from the landfill and enters the environment. Once it enters the environment the leachate is at risk for mixing groundwater near the site which then transports to some distances. Furthermore it has the potential to add biological oxygen demand (BOD) to the groundwater. BOD measures the rate of oxygen uptake by micro-organisms in a sample of water at a temperature of 20 oC and over an elapsed period of five days in the dark.
Food wastes have high energy content. Consequently, it offers a good potential for feed stock for gasification in power plants. Food waste gasification helps to solve two major problems at the same time. Gasification of food waste reduces landfill problems and efficiency. The results show that food wastes offers a good potential for thermal treatment of the waste with the specific aim of power generation. The average proximate analysis of food wastes is 80% volatile matter, 15% fixed carbon, and 5% ash. The volatile matter can be easily destructed in a relatively short period of time, extending from 8 to 12 min at reactor temperatures from 700 to 1000 oC . Energy recovery from volatile components in food wastes can be recovered using a simple pyrolysis process. However, in order to consume the residual fixed carbon after the pyrolysis, the sample must undergo a gasification process. Gasification of a food waste sample includes a pyrolysis part and a char gasification part. Char gasification reactions are slower than that of pyrolysis and consequently, is the rate limiting step in the overall gasification process.
(Source: I.I. Ahmed, A.K. Gupta. Pyrolysis and gasification of food waste: Syngas characteristics and char gasification kinetics. Applied Energy 87 (2010) 101–108)
Stress-induced hyperglycemia and high levels of insulin resistance are prevalent in critical care [1-4]. Increased counter-regulatory hormone secretion stimulates endogenous glucose production and increases insulin resistance [3,4], elevating equilibrium glucose levels and reducing the amount of glucose the body can utilize with a given amount of insulin. Hyperglycemia worsens outcomes, increasing the risk of severe infection, myocardial infarction, and critical illness polyneuropathy and multiple organ failure.
In this study, "virtual trials" are performed using a clinically validated model [15-17] of the glucose-insulin system. Insulin sensitivity, SI, is used as the critical marker of a patient's metabolic state and is assumed independent of the insulin and nutrition inputs. Virtual trials can be used to simulate a TGC protocol using a SI(t) profile identified hourly from clinical data and different insulin and nutrition inputs. Virtual trials enable the rapid testing of new TGC intervention protocols, as well as analysis with respect to glycemic control protocol performance, safety from hypoglycaemia, clinical burden, and the ability to handle dynamic changes in patient metabolic state [15,18]. They are thus a means of safely optimising protocols prior to clinical implementation.
(Source: Chase J.G. et al. Validation of a model-based virtual trials method for tight glycemic control in intensive care. BioMedical Engineering OnLine 2010, 9:84, http://www.biomedical-engineering-online.com)