I am writing my undergraduate thesis paper on a topic in which a lot of work has been done. So, it is important to maintain the flow of progress of my subject of interest through out the years. As, a result I often see a lot of work of many different researchers in the related/relevant work section. It is not possible to go through all of these papers. So, I am trying to paraphrase their work as mentioned in the relevant work section. Now, how am I going to cite the work of the original authors.
Usually you do something like:
"Bla bla." (Murray, 1987, quoted from Harper, 2001)
And you list both sources in your reference list. The actual format will differ depending on the style guide you use (the above is APA).
But this is discouraged, because it means that you basically have no idea about the contents of the original article. It could be misrepresented in the article that quotes it. All you know is a sentence out of context.
In my field (psychology) we may only quote what we have read ourselves. That there is too much to read is not an acceptable excuse. Limit the scope of your research project, or take the time to read the relevant literature.
The only situation where you can quote through a third text is if the original source is impossible for you to get with reasonable effort, like very old sources that you would have to read in the natonal library of some foreign country, or documents in private hands (like letters). For everything else there is interlibrary loan. And if the publication is hidden behind a paywall, most authors are happy to mail you a PDF of their article, if you are doing research. Just explain your affiliation (where you study) and what research you are doing.
I'm currently in the process of writing a PhD thesis myself. Here in Russia we have a requirement that each PhD work shall include a chapter on the current state of the theme in the scientific community. The aspirant (PhD-to-be) is supposed to read at least some of them (most relevant to his/her particular theme, most cited, etc) and reference them, like in scientific paper. For example:
Most commonly those works address the use of SLM in optical manipulation to generate multiple traps, but there is considerable number of researchers who shape laser beam into single trap with some specific properties. For example, recent study of Rodrigo et al.  ad- dresses shaping of the light field into an arbitrary 3D-curve, producing a sort of “light rope”. The study contains experimental results of moving microobjects along those curves due to phase gradient. On the other hand, hard DOE — reliefs etched in glass or quartz plate — are also of interest. Huang et al. discovered a way to produce elongated area of high intensity in the path of a laser beam. There is also a number of work done by our colleagues in this area.
The point is, you present some quick summary of all known to you works in your field in one chapter, and then, in other chapters of your thesis you're supposed to just mention them:
It was shown (), that microobjects would move in the direction of the phase gradient, therefore...
And, of course, at the end of thesis you have Bibliography pages in which you state in full all the data on cited works:
 J. A. Rodrigo, T. Alieva, E. Abramochkin, and I. Castro, Opt. Express 21, 20544 (2013).  K. Huang, P. Shi, X.-l. Kang, X. Zhang, and Y.-p. Li, Opt. Lett. 35, 965 (2010).
There are many styles in which to present the bibliography. If you're not constrained by your institution guidelines, take your pick: Zotero or BibTeX are able to format bibliography list in many styles.
UPD: Here, I updated examples, now they are real citations from my text.
We have different types of citations like APA citation style, MLA citation style and Harvard citation style. These styles can be depends upon the educational institutions.