The Howard Roberts' Guitar Book. Written by Howard Roberts and James Stewart.
(1971) Playback Music.
A 50-page guitar manual which splits the difference between a method book and a free-form exposition of essential guitar licks. An all-time classic covering Howard's approach to picking, comping, improvising, fingerboard technique and chord solo playing. Eclectic, insightful and entertaining, like the man.

Super Solos. Written by Howard Roberts with Ron Eschete.
(1977) Playback Music.
A 48-page collection containing eight of Howard's transcribed solos from his entire career with performance notes. The transcriptions, presumably by Eschete, contain fingerings and position markings.

Howard Roberts Guitar Manual: Chord Melody. Written by Howard Roberts.
(1972) Playback Music.
A 58-page treatise on Howard's unique approach to fingerboard harmony.