Mikoláš, Milan, Jiří Žváček, Michal Vaněk, Roman Donocik, Petra Zápalková, and Václav Sotorník. “Testing the Effect of Undermining on Positional Accuracy of the Digital Technical Map of Ostrava in the Přívoz Cadastral District”. Geodesy and Cartography 37, no. 3 (November 1, 2011): 111-118. Accessed December 5, 2021. https://journals.vgtu.lt/index.php/GAC/article/view/5410.