Coba jelasin Lihat pula dari Karl Liebknecht dong

Sara Ann Sewell, "Mourning Comrades: Communist Funerary Rituals in Colonge during the Weimar Republic", German Studies Review, 32(3) 2009, 527-548.

Eric D. Weitz, Creating German Communism, 1890–1990: From Popular Protests to Socialist State. Princeton, New Jersey: Princeton University Press, 1997.

Ottokar Luban, The Role of the Spartacist Group after 9 November 1918 and the Formation of the KPD, in: Ralf Hoffrogge and Norman LaPorte (eds.), Weimar Communism as Mass Movement 1918-1933, London: Lawrence & Wishart, 2017, pp. 45–65.

Karya Karl Liebknecht  di Marxists Internet Archive.