The current reference for the ‘MCAPS’ package:

Dominici F, Peng RD, Bell ML, Pham L, McDermott A, Zeger SL, Samet JM (2006). “Fine Particulate Air Pollution and Hospital Admission for Cardiovascular and Respiratory Diseases,” Journal of the American Medical Association, 295 (10) 1127--1134.

Corresponding BibTeX entry:

  @Article{,
    title = {Fine Particulate Air Pollution and Hospital Admission for
      Cardiovascular and Respiratory Diseases},
    author = {Francesca Dominci and Roger D. Peng and Michelle L. Bell
      and Aidan McDermott and Scott L. Zeger and Jonathan M. Samet},
    journal = {Journal of the American Medical Associaton},
    year = {2006},
    volume = {295},
    number = {10},
    pages = {1127--1134},
    url = {http://www.biostat.jhsph.edu/MCAPS/},
  }