共 51 条
[21]
KAUFMAN H, 1953, 189 MISS STAT COLL A
[22]
KAUFMAN HF, 1949, B U KENTUCKY AG EXP, V528
[23]
KAUFMAN HF, 1944, MEMOIR AG EXP STA CO, V260
[24]
KEY WH, 1953, THESIS WASHINGTON U
[26]
KREITLOW BW, 1956, B AG EXP STA U WISCO, V525
[27]
LEONARD OE, RURAL SOCIAL SYSTEMS, P230
[29]
MATTHEWS JL, 1953, RURAL SOCIAL SYSTEMS, pCH3
[30]
MCLAUGHLIN LK, 1951, THESIS U CALIFORNIA