000 00300nam a2200121Ia 4500
008 191031s9999 xx 000 0 und d
100 _aMukhofadhyay
245 0 _aSources of variation in agriculture productivity
260 _bMacmillen company
260 _c1976
365 _b40.00
942 _cBK
999 _c205556
_d205556