Deržavoochoronni orhany urjadiv A. Denikina ta P. Vranhelja na Pivdni Ukraïny (1918-1920 rr.) = State protective services of the governments of A. Denikin and P. Wrangel in the South of Ukraine (1918-1920) - Bilaj, Jurij Viktorovyč (Dissertatio Ukrainica, 2019)