by Wyszynski, Z.(Warsaw Agricultural Univ. (Poland). Dept. of Agronomy)E-mail:wyszynski@delta.sggw.waw.pl, Roszkowska-Madry, B.(University of Bialystok, Poland. Dept. of Microeconomy), Kalinowska-Zdun, M.(Warsaw Agricultural Univ. (Poland). Dept. of Agronomy), Gozdowski, D.(Warsaw Agricultural Univ. (Poland). Dept. of Agronomy), Laudanski, Z.(Warsaw Agricultural Univ. (Poland). Dept. of Mathematical Statistics and Experimentation)
Published in Scientia Agriculturae Bohemica (Czech Republic)