JONG, R. de. J.R.G. Schuur, Appelscha. Bolwerk van anarchisme en radicaal socialisme. BMGN - Low Countries Historical Review, [S. l.], v. 114, n. 3, p. 445–446, 1999. DOI: 10.18352/bmgn-lchr.5053. Disponível em: https://bmgn-lchr.nl/article/view/URN%3ANBN%3ANL%3AUI%3A10-1-105795. Acesso em: 1 may. 2024.