1. Bercovitch, M.: 1971,Conf. Papers, 12th Int. Conf. on Cosmic Rays, Hobart, 1971 (Univ. of Tasmania); MOD-12,2, 579.
2. Burger, J. J.: 1971,Astrophys. J. 166, 651.
3. Burger, J. J. and Swanenburg, B. N.: 1971,Conf. Papers, 12th. Int. Conf. on Cosmic Rays, Hobart, 1971 (Univ. of Tasmania); MOD-45, 1858.
4. Burger, J. J. and Swanenburg, B. N.: 1972,J. Geophys. Res. 77, 4264.
5. Fisk, L. A.: 1969, Ph.D. Thesis, Univ. of California, San Diego.