Bowman, Joye L. (22 January 2009). "Abdul Njai: Ally and Enemy of the Portuguese in Guinea-Bissau, 1895–1919". The Journal of African History. 27 (3): 463–479. doi:10.1017/S0021853700023276. S2CID162344466.
handle.net
hdl.handle.net
Furtado, Alexandre Brito Ribeiro (2005). Administração e Gestão da Educação na Guiné-Bissau: Incoerências e Descontinuidades [Administration and Management of Education in Guinea-Bissau: Inconsistencies and Discontinuities] (Doctorate thesis) (in Portuguese). Universidade de Aveiro. hdl:10773/1098.
Bowman, Joye L. (22 January 2009). "Abdul Njai: Ally and Enemy of the Portuguese in Guinea-Bissau, 1895–1919". The Journal of African History. 27 (3): 463–479. doi:10.1017/S0021853700023276. S2CID162344466.