aChroma Meter CR-300 is a device manufactured by Minolta Co., Tokyo.
b Schott Color Glass Filters WG-320 and UG-11 are products of Schott AG, Mainz, Germany.
c The R-B meter is a device manufactured for the researchers by the University La Sapienza, Rome.
dTL 10R and TL 09R are lamps manufactured by Philips Lighting Company, Amsterdam, Netherlands.
eSchott WG-335 is a colored glass filter produced by Schott AG, Mainz, Germany.
fGraphPad Prism 4 is manufactured by GraphPad Software Inc., La Jolla, Calif., USA.