Ėkologicheskoe i khoz︠i︡aĭstvennoe raĭonirovanie srednetaezhnoĭ podzony Karelʹskoĭ ASSR : metodicheskie rekomenda︠t︡sii - Volkov, Anatoliĭ Dmitrievich (Nauka--proizvodstvu (Petrozavodsk, Russia), 1989)