Chernyi, A. V., and A. I. Yakimchik. “Recovery of Potential Using Module Values of Its Gradient. 2”. Geofizicheskiy Zhurnal 22, no. 6 (December 1, 2000): 166–183. Accessed October 7, 2022. http://journals.uran.ua/geofizicheskiy/article/view/214576.