GOST 22850 -77 Peredachj spiroidnie.Termini.Opredelenia i obaznachenia (Spiroid Gears – Terms, Definitions and symbols) (in Russian)
GOST 22850 -77 Peredachj spiroidnie.Termini.Opredelenia i obaznachenia (Spiroid Gears – Terms, Definitions and symbols) (in Russian)