“H.P. Van Tuyll Van Serooskerken, The Netherlands and World War I. Espionage, Diplomacy and Survival”. BMGN - Low Countries Historical Review 117, no. 2 (January 1, 2002): 263–264. Accessed November 22, 2024. https://ojstest.minions.amsterdam/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-106534.