Franzén, Bo. “Nils Hybel and Bjørn Poulsen: The Danish Resources C. 1000-1550. Growth and Recession. Leiden, Brill, 2007”. Historisk Tidsskrift 108, no. 2 (februar 28, 2013): 574–580. Set marts 7, 2026. https://tidsskrift.dk/historisktidsskrift/article/view/56382.