@article{ref1,
title="Some Unsolved Problems in Problem Solving",
journal="OR: Operational research quarterly (1953)",
year="1962",
author="Ackoff, Russell L.",
volume="13",
number="1",
pages="1-11",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="1473-2858",
doi="",
url="http://dx.doi.org/"
}