Kuchmins’kaK. Y. “Boundary Versions of the Worpitzky Theorem for Two-Dimensional Continued Fractions”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 66, no. 8, Aug. 2014, pp. 1106–1116, https://umj.imath.kiev.ua/index.php/umj/article/view/2202.