Crumb, R. (Nombre personal)

His Head comix, 1968.

Bukowski, C. There's no business, 1984: CIP t.p. (R. Crumb) copr. p. (Robert Crumb)

Philippe, R. Political graphics, c1982: p. 325 (Crumb, Robert; b. Philadelphia, 1943)

Wikipedia, Sept. 20, 2010 (Robert Crumb, known as R. Crumb; b. Robert Dennis Crumb, Aug. 30, 1943, Philadelphia, Pa.; American artist, illustrator, and musician)

R. Crumb sketchbook, 2017- : volume 2, page following colophon (Robert Crumb)

R. Crumb's music sampler, ℗2005: container (R. Crumb and his Keep-on-Truckin' Orchestra)

Canadiana, December 16, 2019 (access point: Crumb, R.; full name Robert Crumb)