000 00314nam a2200145Ia 4500
008 220421s9999||||xx |||||||||||||| ||und||
020 _c180
040 _aET
100 _aS.P KULSHRESHTHA
245 0 _aTEACHING AT SCIENCES
260 _bR. LAL PUB.
_aMEERUT
300 _a510
500 _a13030
942 _cBK
999 _c19333
_d19333