1. “An Index of Metamerism for Observer Differences,” Proc. Ist AIC Congr. Color 69, Musterschmidt, Göttingen, 1970, pp. 771–784.
2. “Possibilities for Specifying an Index of Observer Metamerism,” Proc. 3rd AIC Congr. Color 77, Adam Hilger, Bristol, 1978, pp. 432–436.
3. A proposal of new standard deviate observers
4. and , Color Science, Wiley, New York, 1967, pp. 430–434.