Linked from
The 9 pages that link to Tristimulus values, each with the reason it gives.
ColorimetryRelated: They summarize the spectral measurement before it is expressed in a color space.
ChromaticityNarrower topic: Chromaticity coordinates are derived by normalizing tristimulus values.
CIE standard observerRelated: The observer’s functions integrate a spectrum into three such values.
Line of purplesRelated: Chromaticity coordinates are derived by normalizing tristimulus values.