Let's say we have an NBMA network (e.g. Frame Relay) and we configure NBMA mode on it.
I found in CBT Nuggets that there must be full-mesh connectivity in an NBMA mode in order to have IP communication between all routers.
However, Cisco Student Guide says that we must have connectivity between each non-DR and DR (PVCs in Frame Relay). In addition, it states that NBMA mode is for full-mesh and partial mesh topologies.