^Eugene TavaresLittératures lusophones des archipels atlantiques : Açores, Madère, Cap-Vert, São Tomé e Príncipe, (Lusophony Literature in the Atlantic Archipelagoes: Azores, Madeira, Cape Vede and São Tomé and Príncipe, L'Harmattan, 2009, p. 217 ISBN9782296075757
^"Certeza" (in Portuguese) (3rd ed.). Jean Piaget University of Cape Verde. Archived from the original on 2012-07-22.