Non-Riemannian Gravity and the Einstein-Proca System
  We argue that all Einstein-Maxwell or Einstein-Proca solutions to general relativity may be used to construct a large class of solutions (involving torsion and non-metricity) to theories of non-Riemannian gravitation that have been recently discussed in the literature. 
T Dereli, M \"Onder, J Schray, R W Tucker, C Wang