Heywood, William ([1921] 2011): «VI - War with Genoa», A History of Pisa. Eleventh and Twelfth Centuries, Cambridge University Press, ISBN 9780511696862; s. 71-81
Doxey, Gary B. (1996): «Norwegian Crusaders and the Balearic Islands», Scandinavian Studies, 68(2); s. 139-160. Sitat: «In the Liber maiolichinus the Norwegian king is referred to only as rex Norgregius, and is recorded as sailing with 100 ships, though the later sagas record sixty.»
Charles Julian Bishko (1975): «The Spanish and Portuguese Reconquest, 1095–1492», A History of the Crusades, Vol. 3: The Fourteenth and Fifteenth Centuries, red. Harry W. Hazard, Madison: University of Wisconsin Press, s. 405.
