TY - JOUR AU - D. Walls AU - C. Kunasz AU - P. Drummond AU - Peter Zoller BT - Physical Review A DA - Jan-07-1981 DO - 10.1103/PhysRevA.24.627 PY - 1981 SP - 627 EP - 630 T2 - Physical Review A TI - Bifurcations and multistability in two-photon processes VL - 24 SN - 0556-2791 ER -