共 6 条
[2]
FRERICHS R, 1946, NATURWISSENSCHAFTEN, V33, P181
[3]
HOSCHL P, 1960, STUDENT SCIENTIFIC P
[4]
KROGER FA, 1955, J ELECTRONICS, V1, P190
[6]
NOBEL DD, 1959, PHILIPS RES REP, V14, P361