This paper says:
"Players can construct a Runology Tower building on any available plot they own, stake worker cards on it, and provide Trifoil Runes to earn Research Points."
White paper 3 says:
"As mentioned in the Special Resources section of the document, the Trifoil Runes resource can only be obtained by workers in a Castle or Keep building. Trifoil Runes are a required resource for scholars to study in order to produce Research Tokens in the Runology Tower building which are needed to unlock each phase of the Ancient Ruins reconstruction project. This makes owning a Castle or Keep quite valuable due to the fact that it is the only way to produce Trifoil Runes."
My Question:
Players building Runology towers on their non-castle or non-keep plots will have to buy their Trifoil Runes from castles or keeps?