00474naa#a2200169#i#450# EN\INFRA-M\bibl\93857 20251216230247.2 2308-4898 20240927b2024####ek#y0engy0150####ca RU Classification of Ruled Surfaces Journal article Moscow INFRA-M Academic Publishing LLC. 2024 9 с. Journal article local Геометрия. 514 Sal'kov N. A. zh-szf.ru