Key points are not available for this paper at this time.
(1955). Interim Report to the Commission Internationale de l'Eclairage, Zurich, 1955, on the National Physical Laboratory's Investigation of Colour-matching (1955) Optica Acta: International Journal of Optics: Vol. 2, No. 4, pp. 168-181.
Stiles et al. (Thu,) studied this question.