共 6 条
[1]
INGRAM JW, 1925, RICE J
[3]
MARCOVITCH S, 1924, TENN AGR EXP STA B, V131
[4]
MARCOVITCH S, 1926, TENN AGR EXP STA B, V134
[5]
SHAFER GD, 1915, MICH AGR EXP STA TEC, V21, P51
[6]
WILCOX JOSEPH, 1926, JOUR ECON ENT, V19, P189