Citing works in a list without having read them I know this may seem a duplicate question, but I haven't find an answer to my question and I am scared to ask my supervisor.
I am doing my literature review in sociolinguistics and I have different reputable sources: articles and books.
Most of the authors quote the same famous works while describing that they made a contribution to the discipline.
Many of these works are well known and not easy to find (old).
So, is it ok if I write "[...] These themes were examinated by other scholars (e.g. Smith 1970, Doe 1977)", without having read those two books by Smith and Doe, but having read reviews and studies that explain them?
I have just read a dissertation which was written in less than 1 year after fieldwork and it has hundreds or references: I can't imagine the author actually read it. It seems common to me.
Can somebody clarify?
There are two answers that are not logically exclusive: 


When you cite something, you should be reasonably certain that the source pertains to the situation and that you are representing its information accurately. 
Many scholars cite materials they have not read closely, have read in parts, or that they have read through another source. 


Usually, you need to read or at least consult a source in order to verify that your understanding of the source is correct. 

For example, in my field (English), I read most texts I cite, since many texts are primary or archival sources that I interpret closely, or secondary sources that I engage with directly. I need a high level of understanding to respond to other scholars directly. However, there are some secondary sources that provide minor support to what I write. I skim, reading enough to understand the argument or to find the chapter or section I needed. I've never cited a source without at least looking at it. 

In many STEM fields, the tendency is to cite more and with infrequent quotation. Especially in introductions or literature reviews, providing a representation of available knowledge is more important than responding to an individual author or argument. For many of these sources, the texts may have been read or skimmed, in whole or in part. For an article, they may only read the abstract and the results. How close they read those sources often depends on the level of specificity in their reference. Is it one of several works on a rat behavior, or are you indicating a specific result? At a minimum, I'd expect such authors to look at the source, even if they don't read in full. 

In whatever field you're in, the presumption is that the cited fact or argument is accurate. So you are responsible for certifying that the information is accurate. If you use the source extensively, you should read it. If you use the source quickly, you should at least look at it and double-check its credibility, even if you don't read it in full. Don't rely on secondary summary alone. The Office of Research Integrity (a unit of HHS) has this advice in an article titled "Citing Sources that Were Not Read or Thoroughly Understood": 


  The reader should note, however, that there might be instances in which the practice of citing sources that were not read may be acceptable. For example, an author may simply wish to point out a well-known discovery or theory and provide the reader with the original citation. When this is done without misleading the reader into believing that the author read the paper detailing the discovery and is thoroughly acquainted with its contents, then no real harm is done. For example, in a paper on intelligence testing I may want to refer the reader to the psychometric properties of the X test and write: “for a review of validity of reliability of X test see reference Y”. Although I am clearly aware that reference Y reviews validity and reliability for various intelligence tests, including test X, my citation of this work does not imply that I have read and processed its contents. I am merely aware that relevant material may be found in that reference and point the reader to it. However, if in a different paper I were to write that “Smith (1879) studied the effects of X on Y and concluded that X is as important as Z and both are critical causal variables in the incidence of Y” such a statement strongly suggests that my summary of the study is, in fact, based on my reading of that paper.


ORI rightly points out that whether and how closely you need to read it relates directly to whether I'm claiming an author addresses a general topic or whether I am specifying a result. If I'm doing the latter, I had better ensure with my own eyes that I've seen and understood that result. That is why they provide this general guideline: 


  GUIDELINE 18: Generally, when describing others’ work, do not cite an original paper if you are only relying on a secondary summary of that paper. Doing so is a deceptive practice, reflects poor scholarly standards, and can lead to a flawed description of the work described.