1. M.Bicknell-Johnson Stern’s diatomic array applied to Fibonacci representations Fibonacci Quart 41 no. 2(2003) 169–180.
2. Recounting the Rationals
3. L.Carlitz Fibonacci reprentations Fibonacci Quart 6 (1968) no. 4 193–220.
4. K.Conrad UConn lecture notes https://kconrad.math.uconn.edu/blurbs/grouptheory/SL(2 Z).pdf