https://www.osapublishing.org/josaa/abstract.cfm?uri=josaa-7-4-731 (Publisher version)
Wehrhahn, C., Westheimer, G., & Abulencia, A. (1990). Binocular summation in temporal-order detection. Journal of the Optical Society of America A, 7(4), 731-732. doi:10.1364/JOSAA.7.000731.