Help with datacores and their R&D agents

I’ve searched online and I cannot find any reliable information in regards to which R&D agents, from which corporations, give out RP that gets which Datacores.

I’ve even resorted to searching NPC corps - info - agents - R&D and checking the info on each individual specific agent and still can’t figure out who or where you can get Graviton Physics datacores from?

Does anyone know of any reliable information sources that can point me in the right direction as far as agents/corporations go for specific datacores? Or more specifically, tell me which corporations agents i should be looking into for Graviton Physics and Electronic Engineering? Thanks.