D. J. Jenkins, The cost of linguistic loyalty: Socioeconomic factors in the face of shifting demographic trends among Spanish speakers in the Southwest, in: D. J. Villa / S. Rivera-Mills, Spanish Maintenance and Loss in the U.S. Southwest, 2009, p. 7 ([Internet, 2020-10-07](https://benjamins.com/catalog/sic.6.1.02jen))