00508naa#a2200169#i#450# EN\INFRA-M\bibl\10422 20241224123335.2 2308-4898 20151217b2015####ek#y0engy0150####ca RUS RU Properties of Dupin Cyclide and Their Application. Part 3: The Problem of Apollonius Journal article Moscow INFRA-M Academic Publishing LLC. 2015 11 с. Journal article local Sal'kov N. A. naukaru.ru