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Reference12 articles.
1. Y. M. Cho:Phys. Lett. B,81, 25 (1979).
2. F. S. Heney andA. Patrascioiu:Phys. Rev. D 16, 3021 (1977).
3. G. H. Derrick:J. Math. Phys. (N. Y.),5, 1252 (1964);P. Goddard andD. I. Olive:New developments in the theory of magnetic monopoles, CERN preprint TH. 2445-CERN.
4. G. 't Hooft:Phys. Rev. D,14, 3432 (1976).
5. This question is discussed inR. G. Crewther:Effects of topological charges in gauge theories, CERN preprint TH-2522, andStatus of the U 1 problem, CERN preprint TH-2546.