Pietrzak, Michał Bernard, Justyna Wilk, and Stanisław Matusik. “Analysis of Internal Migration in Poland With Application of the Gravity Model”. Acta Universitatis Lodziensis. Folia Oeconomica, no. 293 (January 1, 2013): 27–37. Accessed December 6, 2025. https://www.czasopisma.uni.lodz.pl/foe/article/view/26910.