You may also perform searching by a particular subject; however, this is NOT recommended. Searching by subject requires that you already know the exact words that describe a subject in the exact order they appear in the database (as with a title or an author search). Because of so many different words that can be used to describe a subject ( i.e. 'pig', 'hog', 'swine', and 'porcine') - not to mention plurals - and that the words may appear anywhere in a subject line consisting of many words, you realize that you pretty much have to be psychic to be able to do an accurate subject search.