Sources can be conditionally divided into primary (primary founts) and secondary (or critical literature). Strictly speaking, the primary sources are not: translation, reader, retellings of other authors, even if they are given in good faith.
If you have no idea about the chosen topic, you should familiarize yourself with the list of compulsory and additional literature offered by the instructor of the academic discipline, on which you are going to write a coursework’s. At the departments there are programs of all academic subject with the indication of the corresponding letters. You can ask the supervisor to tell you the most significant sources.
Who prefers to search the literature on his own, you can start searching from an encyclopedia in which, after an article about a particular phenomenon, a list of the basic literature on this issue is always provided.
Then you should refer to the athenaeum directory. If you know the names of the authors of the works you are interested in, they can be found in the alphabetical catalog. If you neglected the previous tips, then the search should start with a regular catalog. Having received the ordered literature, you will find links to other scientific works, they should also be used by you.
Remember that the search can be delayed because: the necessary books or articles are in the hands of other readers, they are not in the library at all, because they were stolen many years ago, in the books or articles that you issue, the pages you will need be torn out.
In books or articles with promising titles, you will find absolutely nothing suitable for your work.
Working in the catalog, pay attention to the year of publication of the book or article. If you write a term paper on the history of economic thought or the economic history of any country, you can find a lot of interesting and useful in publications, for example, twenty years ago. However, if your topic sounds relevant and up-to-date, avoid materials published long ago. On the contrary, you should strive to get acquainted with the latest works on your topic and use the latest factual and statistical data.