Stockman and Sharpe's template equation
Baylor, Nunn & Schnapf (1984): cynmologus monkey rods
Kraft, Schneeweis & Schnapf (1993): human rods
Baylor, Nunn & Schnapf (1987): cynmologus monkey cones
Bowmaker et al. (1978): Rhesus monkey rods, and M- and L-cones
Dartnall, Bowmaker & Mollon (1983): Human rods and cones
Photobleaching difference absorption spectra [and λmax values] of human cone pigments produced in cultured cells by Merbs & Nathans (1992a,b)