@article{ref1,
title="Making playgrounds safe for children and children safe for playgrounds",
journal="Young children",
year="1979",
author="Henniger, Michael L. and Frost, Joe L.",
volume="34",
number="5",
pages="23-30",
abstract="<p>[Abstract unavailable]</p>  <p>Language: en</p>",
language="en",
issn="0044-0728",
doi="",
url="http://dx.doi.org/"
}