000
00293nam a2200121Ia 4500
008
210901s1920 xx 000 0 eng d
082
_a
537.5 ALF
100
_a
Alfrey, G.F.
245
0
_a
Physical electronics
260
_a
London
_b
D,.Van Norstrand
_c
1920
650
_a
Physics
942
_2
ddc
_c
BK
999
_c
2603
_d
2603