000
00254nam a2200121Ia 4500
008
220201s1992 xx 000 0 eng d
082
_a
500
_b
SIN
100
_a
Singh
245
0
_a
Upkar General Science .
260
_c
1992
300
_a
171
942
_2
ddc
999
_c
6906
_d
6906