@article{ref1,
title="A Human Error Approach to Accident Investigation: The Taxonomy of Unsafe Operations",
journal="International journal of aviation psychology",
year="1997",
author="Shappell, Scott A. and Wiegmann, Douglas A.",
volume="7",
number="4",
pages="269-291",
abstract="[Abstract unavailable]  <p>Language: en</p>",
language="en",
issn="1050-8414",
doi="10.1207/s15327108ijap0704_2",
url="http://dx.doi.org/10.1207/s15327108ijap0704_2"
}