Martnez-Celdrn, Eugenio; Fernndez-Planas, Ana Ma.; Carrera-Sabat, Josefina (Disember 2003). "Castilian Spanish". Journal of the International Phonetic Association. 33 (2): 255–259. doi:10.1017/S0025100303001373. Dicapai pada 18 Mac 2022.
Dalbor, John B. (Mac 1980). "Observations on Present-Day Seseo and Ceceo in Southern Spain". Hispania. 63 (1): 5–19. doi:10.2307/340806. JSTOR340806.
Martnez-Celdrn, Eugenio; Fernndez-Planas, Ana Ma.; Carrera-Sabat, Josefina (Disember 2003). "Castilian Spanish". Journal of the International Phonetic Association. 33 (2): 255–259. doi:10.1017/S0025100303001373. Dicapai pada 18 Mac 2022.