https://www.cambridge.org/core/journals/international-review-of-social-history/article/la-fondation-du-parti-ouvrier-belge-et-le-ralliement-de-la-classe-ouvriere-a-laction-politique-18821886/2A82233375F99C9EEEF884ED0B0A8E7D#
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/2A82233375F99C9EEEF884ED0B0A8E7D/S0020859000002297a.pdf/la_fondation_du_parti_ouvrier_belge_et_le_ralliement_de_la_classe_ouvriere_a_laction_politique_18821886.pdf
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/2A82233375F99C9EEEF884ED0B0A8E7D/S0020859000002297a.pdf/la_fondation_du_parti_ouvrier_belge_et_le_ralliement_de_la_classe_ouvriere_a_laction_politique_18821886.pdf