Bolʹshai︠a︡ sovetskai︠a︡ ėnt︠s︡iklopedii︠a︡ /
Prokhorov, A. M.(Aleksandr Mikhaĭlovich),1916-
Moskva : Sovetskai︠a︡ ėnt︠s︡iklopedii︠a︡,
1970-1978.
Encyclopedias and dictionaries.