Firth, W. et al. "Theory of Spin-flip laser modes - I: Threshold Modulation and Tuning Behavior." IEEE Journal of Quantum Electronics 12/4 (April 1976):218-225.

Firth, W. et al. "Theory of Spin-flip laser modes - I: Threshold Modulation and Tuning Behavior." IEEE Journal of Quantum Electronics 12/4 (April 1976):218-225.