The Critical Edition of Q edited by James M Robinson Paul Hoffmann and John S Kloppenborg and Excavating Q by John S Kloppenborg Verbin
Most New Testament scholars believe that besides following the Gospel of Mark's narrative of Jesus's ministry and passion, the authors of Matthew and Luke independently drew from a common collection of Jesus sayings in composing their Gospels. These books represent nearly two decades of study of the theoretical Q by two of its foremost scholars, James Robinson and John Kloppenborg Verbin (whose recent marriage accounts for his added surname).