Themes Associated with Great Works

Does anyone know which "themes" are associated with which work, or at least where to find them?

It seems like it looks at three things: age, type and civilization. So if they're all of the same age, all artifacts from battles, but from different civs, you get something like "Museum of Ancient Warfare"; if they're all from your civ and from the same era, you get something like, "Gallery of Industrial Assyrian Art" (I played as Assyria earlier and won a cultural victory with a lot of the theming bonuses.) I ended up having to have a scratchpad to keep track of everything when trading with other civs for stuff that was the right civ and era.

The themes are related to the buildings that house the Great Works. If you hover your cursor above the +0 next to a particular building in the tourism overview, it will tell you what combination of works it requires to have a theme. For instance, I believe the Louvre is two works of art and two artifacts, each from a different era and civilization. Other buildings require that the works be from the same era and civilization.