Reprinted from: The American Journal of Psychology, Sept. 1964, v. LXXVII, p. 422-428.
Bibliography
Includes bibliographical references.
Reproduction
Electronic reproduction. Washington, D.C. : FAA. Mode of access: Internet from the FAA web site. Address as of 10/6/06: http://www.faa.gov/library/reports/medical/oamtechreports/1960s/media/AM64-17.pdf; current access is available via PURL.