Osovetskiy, B.M. “Ta-Nb AND TR-MINERALIZATION IN MESOZOIC-CENOZOIC SEDIMENTS OF THE UPPER KAMA BASIN AND PERSPECTIVES OF EXPANDING AND DEVELOPMENT OF MINERAL RESOURCES IN THE REGION”. Perm Federal Research Centre Journal, no. 3, Jan. 2014, pp. 96-108, https://journal-dev.icmm.ru/index.php/pscj/article/view/PSCJ2013n3p9.