ybee et al. 1994

ybee, Joan, Revere Perkins & William Pagliuca. 1994. The Evolution of Grammar: tense, aspect, and modality in the languages of the world. Chicago and London: The University of Chicago Press.

@book{bybee_et_al_1994,
  address   = {Chicago and London},
  author    = {ybee, Joan and Perkins, Revere and Pagliuca, William},
  publisher = {The University of Chicago Press},
  title     = {The Evolution of Grammar: tense, aspect, and modality in the languages of the world},
  year      = {1994}
}