1. Akimov, V. V. and 75 co-authors: 1988a, Space Sci. Rev. 49, 111.
2. Akimov, V. V. and 45 co-authors: 1988b, Space Sci. Rev. 49, 125.
3. Akimov, V. V. and 20 co-authors: 1991, 22nd Int. Cosmic Ray Conf. 2, 483.
4. Akimov, V. V. and 32 co-authors: 1991, 22nd Int. Cosmic Ray Conf. 3, 73.
5. Akimov, V. V., Leikov, N. G., Belov, A. V., Chertok, I. M., Kurt, V. G., Magun, A., and Melnikov, V. F.: 1993, 23th Int. Cosmic Ray Conf. 3, 111.