共 43 条
[22]
MEYERS RP, 1938, Patent No. 2128845
[23]
OWEN WL, 1953, Patent No. 2624692
[24]
PEEBLES DD, 1948, Patent No. 2439612
[26]
SCHAEPPI JH, 1950, Patent No. 272240
[27]
SHARP PF, 1951, Patent No. 2565097
[28]
SHARP PF, 1951, Patent No. 2565098
[29]
Stimpson EG, 1954, U.S. Patent, Patent No. [2668765, 2.668,765.]
[30]
WALLACE A, 1951, Patent No. 2555211