What does GameEffects.xml link to

[The Kings Raven]

I'm trying to give a building adjancey bonuses that grant great people points depending on which other districts are adjacent. Looking at the existing adjacent bonuses (Meiji Restoration and Stave Church) both of them reference GameEffects.xml however GameEffects.xml only has the names of different effects and nothing to control what they actually do.

Obviously the actual results of those effects are defined in a separate file; but I cannot find which one. Does anyone know?