Covarrubias Acosta, A. “The Importance of Recognizing Ghost Speakers in Linguistic Revitalization Projects: Experience With San Bartolo Yautepec Zapotec”. Annals of Anthropology, vol. 55, no. 2, July 2021, pp. 23-35, doi:10.22201/iia.24486221e.2021.77239.