Opyt srednemasshtabnoĭ topomineralogii : Paĭkhoĭsko-︠I︡Uzhnonovozemelʹska︠i︡a mineralogicheska︠i︡a provin︠t︡si︠i︡a - ︠I︡Ushkin, Nikolaĭ Pavlovich ("Nauka," Leningradskoe otd-nie, 1980)