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Steven Kreis (30. 1. 2008). „Karl Marx, 1818-1883”. The History Guide.CS1 одржавање: Формат датума (веза)
Strube, Julian (2016). „Socialist religion and the emergence of occultism: a genealogical approach to socialism and secularization in 19th-century France”. Religion. 46 (3): 359—388. S2CID147626697. doi:10.1080/0048721X.2016.1146926.