Bak, János M., 1929-. Studying Medieval rulers and their subjects. - Farnham [u.a.] : Ashgate. - 2010 [Rezension] - Krieb, Steffen (. Historische Zeitschrift. - [Berlin] : de Gruyter Oldenbourg, 1859-. - ISSN 0018-2613 296, 2013)