共 4 条
[1]
LIEBKNECHT O, 1942, Patent No. 2267831
[2]
PERMUTIT CO, 1942, Patent No. 539884
[3]
*RES PROD CHEM CO, 1941, AMBERLITES
[4]
*U CAL CITR EXP ST, PAP U CAL CITR EXP S, V479