Spruce gall-aphid
Herrick, G.W., Tanaka, T.
Spruce gall-aphid - Ithaca 1926 - 1-17 p. - Cornell Agricultural Experiment Station. Bulletin No. 454 .
Spruce gall-aphid - Ithaca 1926 - 1-17 p. - Cornell Agricultural Experiment Station. Bulletin No. 454 .