William A. Thornton, "The Prime Colors of Human Vision: Their Prescription for Illumination, Color Printing, Color Photography, Color Television, and Visual Clarity" in Proc. IS&T CGIV 2002 First European Conf. on Colour in Graphics, Imaging, and Vision, 2002, pp 56 - 60, https://doi.org/10.2352/CGIV.2002.1.1.art00013