Measurement of light and colour sensations : a new method of investigating the phenomena of light and colour by means of the selective absorption in coloured glass, graded into scales of equivalent colour value
Lovibond, Joseph W. (Joseph Williams), 1835-1918, George Gill and Sons, publisher · London : George Gill and Sons, Minerva House, Warwick Lane, E.C. · leaf 58
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Color · Light · Optics
Internet Archive · Getty Research Institute · Public domain. Free to use for anything.
