Although many journals of rhetoric and communication are now indexed online, Matlon remains the definitive index for scholarly journals pre-1990. Journals are represented as TOCs and are indexed by author and subject.
Contains extended entries explaining rhetorical genres and devices such as ethos, pathos, enthymeme, epideictic, credibility, and persuasion. Print volume is in Ladd Reference: PN172 .E52 2001
Also good for rhetorical devices, genres, and styles. The bibliographies associated with each entry are excellent. Print copy available in Ladd Reference: PN172 .J37 2001
Basic background information on communications and media. Look here for broadcasting as it affects communication. Not useful for Aristotelian rhetoric.