Polish botanical studies 11990 / Editor Zbigniew Mirek . Kraków :  Academy of sciences , 1991 . 200 s . ISSN 0867-0730 . [1, of that borrowed 0]

1991 Corn performance tests / Editor Roger D. Gipson . Athens :  University of Georgia , 1991 . 37 s . ISSN 0072-128X . [1, of that borrowed 0]