Reader's Guide to Music: History, Theory, and Criticism
This work is designed as a guide to the number of English language book-length studies in music. Each entry consists of a bibliography of some 3-20 titles and an essay in which these titles are evaluated, by an expert in the field.
Block, Geoffrey. "Gershwin." In Reader's Guide to Music: History, Theory, and Criticism, edited by Murray Steib, pp. 257-58. Chicago and London: Fitzroy Dearborn Publishers, 1999.