Reference: Pollard and Sag 1994

Pollard, Carl & Ivan A Sag. 1994. Head-driven phrase structure grammar. University of Chicago Press.

@book{pollard1994hpsg,
  author    = {Pollard, Carl and Sag, Ivan A},
  publisher = {University of Chicago Press},
  title     = {Head-driven phrase structure grammar},
  year      = {1994}
}