1. Soliton Evolution in the Presence of Perturbation
2. A perturbational approach to two-soliton systems;Karpman;IZMIRAN preprints, Part I: No. 34 (262),1979
3. A perturbational approach to two-soliton systems;Karpman;IZMIRAN preprints, Part II: No. 35 (263),1979
4. The influence of external perturbations on solitons in Josephson junctions;Karpman;IZMIRAN preprint, No. 28 (294),1980