1. Andrew, B. H., Branson, N. J. B. A. and Wills, D.: 1964,Nature 203, 171.
2. Apparao, K. M. V.: 1973,Astrophys. Space Sci. 25, 3.
3. Armstrong, J. W. and Coles, W. A.: 1978,Astrophys. J. 220, 346.
4. Bobeiko, A. L., Bovkoon, V. P., Braude, S. Ya., Megn, A. V. and Sergienko, Yu. Yu.: 1978a, in A. A. Pistolkors (ed.),Coll. ?Antennae? 26, 121.
5. Bobeiko, A. L., Bovkoon, V. P., Braude, S. Ya., Megn, A. V. and Rashkovsky, S. L.: 1978b,XI Soviet Radio Astronomy Conf., Digests, p. 261.