Łukowski, J., and M. Kaczmarek. “Laboratory Methods of Determination of Pore Structure Parameters: Formation Factor and Tortuosity of Permeable Media by Electric Methods”. Engineering Transactions 50, no. 4 (December 31, 2002): 267–286. Accessed April 7, 2026. https://et.ippt.pan.pl/index.php/et/article/view/532.