@booklet {1517,
	title = {Adaptive testing (Final Report Contract OPM-29-80)},
	year = {1984},
	address = {Urbana-Champaign IL: University of Illinois, Aviation Research Laboratory},
	author = {Trollip, S. R.}
}
@booklet {1518,
	title = {An adaptive Private Pilot Certification Exam},
	year = {1982},
	address = {Aviation, Space, and Environmental Medicine},
	author = {Trollip, S. R. and Anderson, R. I.}
}
