Robertson 1987

Robertson, John. 1987. The common beginning and evolution of the Tense-Aspect system of Tzotzil and Tzeltal Mayan. International Journal of American Linguistics 53. 432-444.

@article{tseltal-R024,
  author  = {Robertson, John},
  journal = {International Journal of American Linguistics},
  pages   = {432-444},
  title   = {The common beginning and evolution of the Tense-Aspect system of Tzotzil and Tzeltal Mayan},
  volume  = {53},
  year    = {1987}
}