共 12 条
[1]
AREND W, 1960, Patent No. 2966496
[4]
DRECHSEL EK, 1957, Patent No. 2818362
[5]
DRECHSEL EK, 1957, Patent No. 2818399
[6]
HICKNER RA, 1966, Patent No. 3228955
[7]
HOMEYER AH, 1958, Patent No. 2437390