Bórawski, P., and A. Lewczuk. “LOGIT MODEL UTILIZATION IN ADDITIONAL AND ALTERNATIVE INCOME ESTIMATION OF FARMS”. Journal of Agribusiness and Rural Development, Vol. 13, no. 3, Dec. 2009, pp. 33-39, http://www1.up.poznan.pl/jard/index.php/jard/article/view/870.