00643naa#a2200169#i#450# EN\\bibl\83968 20240824184436.6 2712-7761 20240611b2024####ek#y0engy0150####ca RU From teaching experience. XIV. On the variety of tetrahedrons Journal article Syktyvkar FSBI FIC "Komi Scientific Center of the Ural Branch of the Russian Academy of Sciences" 2024 3 с. Journal article local Учение о симметрии. Учение о простых формах. 548.12 Voytehovskiy Yuri Leonidovich komisc.editorum.ru