000 00293nam a2200097Ia 4500
001 23488
008 170722s9999 xx 000 0 und d
245 _aCovalent compounds unit 10. 1971
_bOPEN UNIVERSITY,SCIENCE FOUNDATION COURSE TEAM. /
260 _bOpen University Press ,
_c1971.
942 _cGEN
999 _c94934
_d94934