1. Asymptotic theory of wave propagation;Lewis;Archs ration. Mech. Analysis,1965
2. Kinematic wave theory;Hayes,1970
3. Progressive Waves;Germaine;Jber. DGLR,1971
4. Reductive perturbation method and far fields of wave equations;Taniuti;Prog. theor. Phys. Suppl.,1975