Bibliographies are a good place to begin. They supplement the more basic lists of important works which you can find in encyclopaedias, providing either selective or exhaustive lists of books on the complete range of subjects. Items to be included in a bibliography may be selected in a variety of ways. Selection could, for example, be made on the basis of publication date the list comprising all works published before a certain date or later than a certain date. It will be clear from the title or the introduction what are the criteria for inclusion.
Exhaustive works try to list everything written about the subject.
Some bibliographies contain annotations which describe the contents of the works listed. These are very useful in helping you to get a feel of the subject and in helping you to decide which books you will need to use. Because subject bibliographies are compiled relatively infrequently you will probably need to use bibliographies and references given in recent books on your subject or in the serial publications which describe recent developments in various subject areas. Use a reference work. BES in the Thomas Parry Library.