Kropsz, I., and A. Słociak. “PROFITABILITY OF ZUCCHINI PRODUCTION AT DIFFERENT METHODS OF CULTIVATION”. Acta Scientiarum Polonorum. Oeconomia, Vol. 3, no. 2, Dec. 2004, pp. 85-98, https://js.wne.sggw.pl/index.php/aspe/article/view/3634.