Kaljusaar, Kristjan. (2015). Hostages in the Baltic Crusades, Wars of Conquest and Cultural Exchange during the 12th and 13th Centuries. (EST: Pantvangid ning Läänemere ristiretked, vallutussõjad ja kultuurivahetus 12.-13. sajandil). Master thesis. Supervisor: Anti Selart. University of Tartu, Faculty of Philosophy, Institute of History and Archaeology.
Read the thesis (ENG summary on p. 111-1115): here.
