System of suffixal negations in Permian languages report at the Presidium of the Science Centre of the Ural Division of the USSR Academy of Sciences ; 5 july, 1990 - Cypanov, Evgenij Aleksandrovič 1960- (1990)
PST: Sistema suffiksal'nogo otricanija v permskich jazykach. - Text in kyrill. Schr., russ. - Text russ. - Zsfassung in engl. Spr