1. A. Sommerfeld, Vorlesungen uber Teoretische Physik. Band IV. Optik. Wiesbaden, 1950.
2. Speed of strength light pulse in inversely excited medium;Basov;Sov. Phys. Dokl. URSS,1965
3. Nonlinear enhance of light pulse;Basov;Sov. Phys. JETF,1966
4. On the passing of mono light pulse through enhance and absorption medium;Samson;Sov. Phys. Dokl. BSSR,1966
5. Linear pulse propagation in an absorbing medium;Chu;Phys. Rev. Lett.,1982