Sevost’yanov, E. A. “On the Sets of Branch Points of Mappings More General Than Quasiregular”. Ukrains’kyi Matematychnyi Zhurnal 62, no. 2 (February 25, 2010): 215–230. Accessed May 2, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/2858.