Russo, Ron (2006) [1979]. Field Guide to Plant Galls of California and Other Western States. California Natural History Guide No. 91 (Rev. ed.). Berkeley, Calif.: University of California Press. p. 204. ISBN978-0-520-24886-1. LCCN2006009332. OCLC65207054.
Russo, Ron (2006) [1979]. Field Guide to Plant Galls of California and Other Western States. California Natural History Guide No. 91 (Rev. ed.). Berkeley, Calif.: University of California Press. p. 204. ISBN978-0-520-24886-1. LCCN2006009332. OCLC65207054.