Veretennikov М. “Locum Tenens of the Patriarchal Throne Metropolitan of Kazan and Sviyazhsk Ephraim and the Way of the Russian Church in the Time of Troubles”. Theological Bulletin, no. 4 (31), Dec. 2018, pp. 123-62, doi:10.31802/2500-1450-2018-31-4-123-162.