1. CIE Publication 80: Special metamerism index: Change in observer. Central Bureau of the CIE, Vienna (1989)
2. Nayatani, Y., Takahama, K., Sobagaki, H.: A proposal of new standard deviate observers. Color Res. Appl. 8(1), 47–56 (1983)
3. Takahama, K., Sobagaki, H., Nayatani, Y.: Prediction of observer variation in estimating colorimetric values. Color Res. Appl. 10(2), 106–117 (1985)
4. Nimeroff, I., Rosenblatt, J.R., Dannemiller, M.C.: Variability of spectral tristimulus values. J. Opt. Soc. Am. A 52, 685–691 (1962)
5. Wyszecki, G., Stiles, W.: Color Science: Concepts and Methods, Quantitative Data and Formulae, 2nd edn. Wiley, New York (1982)