共 28 条
[6]
COCHRAN WG, 1963, SAMPLING TECHNIQUES, P59
[7]
Dawson M., 1997, State Veterinary Journal, V7, P16
[9]
*EUR COMM, 2002, FIN REP UPD ASS GEOG
[10]
*EUR COMM, 2002, STRAT INV POSS PRESS