000 00319nam a2200121Ia 4500
008 211228s9999 xx 000 0 und d
040 _cJayakar Knowledge Resource Centre
100 _aEngels, Frederic
245 0 _aDialectics of nature
260 _bProgress
_aMoscow
_c1964
653 _aNatural science
942 _c1
999 _c201928
_d201928