1. (1) I. Namba, Naoya Hara, Tarow Noguchi: Study on readability of chromatic document Part 2 — Relationship between visual factors of chromatic document with achromatic background and readability —, Record of the 2002 Kansai-Section Joint Convention of Institutes of Electrical Engineering JAPAN, p. G300 (2002).
2. (2) Study on readability of chromatic document Part 2 — Relationship between visual factors of chromatic document with achromatic background and equivalent luminance contrast —, Record of the 2002 Kansai-Section Joint Convention of Institutes of Electrical Engineering, JAPAN, p. G301 (2002).
3. (3) Chapter 4 Color system: Handbook of Color Science [second edition], color associ. of Jpn.: University of Tokyo press, pp. 87-129 (1998).
4. (4) Chapter 5 Color order system: Handbook of Color Science [second edition], color associ. of Jpn.: University of Tokyo press, pp. 131-175 (1998).