Vǔlkov, Georgi: Racho Petrov – nachalnik-shtab na bǔlgarskata voyska v Srǔbsko-bǔlgarskata voyna 1885 g. (Racho Petrov – Chief of staff of the Bulgarian army in the Serbo-Bulgarian War 1885), in: Izvestiya na Instituta za voenna istoriya i Voennoistoricheskoto druzhestvo (Notifications of the Institute of Military History and the Military History Society) 50, 1990.