000 00304nam a2200097Ia 4500
008 230930s9999||||xx |||||||||||||| ||und||
100 _aCampbell,Donald T. Julian C.Stanley
245 0 _aExperiment and Quasi-Experimental Designs For Research
260 _aUSA
260 _bHoughton Mifflin Company Boston
999 _c20686
_d20686