Krauer, Philipp. “Welcome to Hotel Helvetia! Friedrich Wüthrich’s Illicit Mercenary Trade Network for the Dutch East Indies, 1858-1890”. BMGN - Low Countries Historical Review 134, no. 3 (September 26, 2019): 122–147. Accessed June 28, 2022. https://bmgn-lchr.nl/article/view/6978.