000			00403nam a2200145Ia 4500
008			140215s9999 xx 000 0 und d
020			_a0 8039 0581 5
084			_aY _bBER;1975
100			_aBernstein, I N.
245			_aValidity Issues in Evaluative Research / _b
260			_bSage Contemporary social Science Issues , _aLondon : _c1975
300			_a134p :
650			_aExtension
942			_2cc _cBK
999			_c12350 _d12350