000 00307nam a2200109Ia 4500
008 220421s1991 xx 000 0 und d
041 _aeng
082 _a500
_bRAO/SCI
100 _aRao ,Digumarti Bhaskara.
_9571436
245 _aScience and Technology Education
260 _aNew Jersey
_b Prentice Hall
_c1991
999 _c397663
_d397663