Smith, Dorman H. Guitar and Lute Music in Periodicals: an Index. Berkeley, CA: Fallen Leaf Press, 1990.
ML128 .G8 S64 1990 MUSIC REFERENCE
Index of music published in six major American guitar periodicals: Chelys (continued by Electric Chelys), Guitar & Lute, Lute Society of America Journal, Lute Society of America Newsletter, Guitar Review, and Soundboard. Entries include composer, title, instrumentation, source and arranger.
The Music Index. Warren, MI: Harmonie Park Press.
ML118 .M84 MUSIC REFERENCE
An index of articles, reviews and obituaries collected from music periodicals around the world. It is physically available in Music Reference from 1949-2001, online from 1978 to present. It is organized by subject, and covers both classical and popular music. There are several subjects related to guitar, easily found under "guitar," along with cross-references.