J.A. A Dictionary of Literary Terms. The two sources are best used together, since information in each is complementary. Hammond, N.G.L. and H.H. Scullard, eds. The Oxford Classical Dictionary. The source for quickly and fully tracing allusions to the Greco-Roman literary, cultural, and historical background of English and American literature.
Many entries are long and include bibliographic references.
Holman, Hugh C. and William Harmon. A Handbook to Literature. Defines literary or literary-related terms, persons, or periods. Magill, Frank N., ed. Great Women Writers.