共 5 条
[1]
ALLEN D. G., 1959, JOUR ECON ENT, V52, P482, DOI 10.1093/jee/52.3.482
[2]
GERMAIN CJ, 1967, RM87 US FOR SERV RES
[3]
LYON RL, 1971, PSW249 US FOR SERV R
[4]
RUDINSKY J. A., 1959, JOUR ECON ENT, V52, P485, DOI 10.1093/jee/52.3.485