Kujawiak, S., J. Bykowski, R. Mazur, K. Ziemblińska, and J. Nyćkowiak. “Cost-Efficiency of Rainwater Collecting Systems for Individual Household”. Journal of Agribusiness and Rural Development, Vol. 34, no. 4, Dec. 2014, pp. 91-98, http://www1.up.poznan.pl/jard/index.php/jard/article/view/466.