Ėkstremalʹnye raĭony : voprosy khoz︠i︡aĭstvennogo osvoeni︠i︡a i strukturnykh sdvigov : sbornik nauchnykh trudov - Kibalʹchich, Oleg Alekseevich; Lazhen︠t︡sev, Vitaliĭ Nikolaevich (Komi nauchnyĭ ︠t︡sentr UrO RAN, 1991)