In the present Transactions there are works by collaborators in the Theoretical Physics Department at the Institute of Physics of the Latvian Academy of Sciences, containing results of the work on collision theory during 1960-61. Papers by L. A. Vainstein, collaborator of the Physics Institute named P. N. Lomonosov, and by G. F. Drukarev and V. D. Obiedkov, collaborators of the Leningrad State University named A. A. Zdanov, are also included.