An instrument for the measurement of the visual quality of displays. - Gerd P. J. Spenkelink; Ko Besuijen; Jacco Brok (Behav. Inf. Technol., 1993)

The perception and measurement of contrast: the influence of gaps between display elements. - Gerd P. J. Spenkelink; Ko Besuijen (Behav. Inf. Technol., 1994)