Dr Michael Kok has assembled a useful list of scholarship and resources on the Q hypothesis, the theory that, in addition to their use of the Gospel of Mark, Matthew and Luke independently used an extensive second source (Quelle) to compose their gospels.
Kok divides the scholarship and resources into the following categories:
- The Synoptic Problem and the Case for/Against Q
- The Text of Q as reconstructed from Matthew/Luke
- Theories about Q and Christian Origins