“SYNTHESIS AND PROPERTIES OF COMPOUNDS YBa2-xSrxCu3O7 AND YBa2-xCaxCu3O7: UDC 546.64.43.55”. Bulletin of Taras Shevchenko National University of Kyiv. Chemistry, vol. 52, no. 1, Dec. 2016, pp. 24-25, https://chemistry.bulletin.knu.ua/en/article/view/8581.