1. König, A., Verh. dtsch. phys. Ges., Berlin11 (1892) 10; Ann. Phys.45 (1892) 604; Ges. Abh. Leipzig 1903, pp. 244–213, 1911.
2. Bouma, P. J., Philips techn. Rev.1 (1936) 142.
3. Bouma, P. J., Physica8 (1941) 413.
4. Bouma, P. J., Proc. roy. Acad., Amsterdam38 (1935) 35, 148.
5. Bouma, P.J., Physical aspects of colour, Philips techn. and sci. Literature Dept., 1948.