“Aircrew Survey Project”
by Dr. Richard F. Haines ant Ted Roe, 2001 (NARCAP)
The paper presents the results of a confidential aircrew survey presented to 298 currently rated and flying commercial pilots employed by a U.S. airline, according to Haines and Roe:
http://www.narcap.org/reports/005/narcap.survey.pdf
(ovnis-usa.com/narcap.org image)