000 00306nam a2200121Ia 4500
001 81799
008 170722s9999 xx 000 0 und d
100 _aTharp, Roland G. And
245 _aBehaviour modification in the natural environment /
260 _c1969.
700 _aWetzel, Ralph J.
942 _cGEN
999 _c76007
_d76007