We study dynamics and bifurcations of two-dimensional reversible
maps having non-transversal heteroclinic cycles containing symmetric saddle fixed
points. We consider one-parameter families of reversible maps unfolding the
initial heteroclinic tangency and prove the existence of infinitely many sequences
(cascades) of bifurcations and birth of asymptotically stable, unstable and elliptic
Delshams, A. [et al.]. Abundance of attracting, repelling and elliptic periodic orbits in two-dimensional reversible maps. "Nonlinearity", 01 Gener 2013, vol. 26, p. 1-33.