共 9 条
[1]
Bruce D, 1925, J AGRIC RES, V31, P0923
[2]
GATES F. C., 1930, JOUR FOREST, V28, P395
[5]
Lutz HJ, 1930, J AGRIC RES, V41, P0561
[7]
MOREY HF, 1935, UNPUB ALLEGHENY FORE
[8]
SUDWORTH GB, 1927, 92 USDA MISC CIRC
[9]
[No title captured]