Zorya RS, Sitdikov AG. N.F. KALININ: STUDYING AND PRESERVING THE HISTORICAL AND ARCHAEOLOGICAL HERITAGE OF BOLGAR FORTIFIED SETTLEMENT. АЕС [Internet]. 2021 Apr. 30 [cited 2026 Nov. 7];(2):346-60. Available from: https://www.evrazstep.ru/index.php/aes/article/view/92