Sjaak van der Velden, Van SDB to SP. 125 jaar socialisme in Nederland. TSEG - The Low Countries Journal of Social and Economic History, [S. l.], v. 6, n. 2, p. 117–118, 2009. DOI: 10.18352/tseg.449. Disponível em: https://tseg.nl/article/view/7719.. Acesso em: 3 jul. 2024.