Why did Kazan diocese have no archbishop in 1574–1575? (some notes on the history of Church governance in Russia in the 16th century) - Andrei Usachev (Vestnik Pravoslavnogo Svâto-Tihonovskogo Gumanitarnogo Universiteta: Seriâ II. Istoriâ, Istoriâ Russkoj Pravoslavnoj Cerkvi, 2022)