Markish, A. A., R. R. Salimov, and E. A. Sevost’yanov. 2018. “On the Lower Estimate of the Distortion of distance for One Class of Mappings”. Ukrains’kyi Matematychnyi Zhurnal 70 (11), 1553-62. https://umj.imath.kiev.ua/index.php/umj/article/view/1659.