@article{ref1,
title="Generalizability in pediatric injury research: lumping vs. splitting",
journal="Pediatric emergency care",
year="1987",
author="Christoffel, Katherine Kaufer",
volume="3",
number="4",
pages="271-276",
abstract="Abstract unavailable.",
language="",
issn="0749-5161",
doi="",
url="http://dx.doi.org/"
}