1. “Nonlinear Laser Spectroscopy”;Letokhov,1977
2. Nonlinear narrow optical resonances induced by laser radiation;Chebotayev,1977
3. Nonlinear high resolution spectroscopy of atoms and molecules;Hänsch,1977
4. Three level laser spectroscopy;Chebotayev,1976
5. “Laser Spectroscopy,”;Demtroder,1981