Bybee et al. 1994

Bybee, Joan L. and Perkins, Revere D. and Pagliuca, William. 1994. The evolution of grammar: Tense, aspect and modality in the languages of the world. Chicago: University of Chicago Press.

@book{jacquesestimative-bybee94TAM,
  author    = {Bybee, Joan L. and Perkins, Revere D. and Pagliuca, William},
  publisher = {Chicago: University of Chicago Press},
  title     = {The evolution of grammar: Tense, aspect and modality in the languages of the world},
  year      = {1994}
}