Resende, Maurício. “Modal verbs’ morphology:: Remarks on the Morphological Characterization of Dever (‘must’), Poder (‘can’/‘may’), and Ter que/De (‘have to’)”. Revista da Anpoll 52, no. 1 (May 31, 2021): 236–256. Accessed October 12, 2025. https://revistadaanpoll.emnuvens.com.br/revista/article/view/1472.