000 00391nam a2200121Ia 4500
001 MPKV056898
008 120911s9999 xx 000 0 und d
082 _a630
245 _aProcceding of the national Academy of science Vol.71 No.10-12
_c;
246 _aProcceding of the national Academy of science Vol.71 No.10-12
260 _aUSA
_bNational Academy of science
_c1974
650 _aAgronomy
999 _c54892
_d54892