1. R. M. Sternheimer: inMethods of Experimental Physics, edited byL. C. L. Yuan andC. S. Wu (New York, 1961), Vol.5 A, p. 1.
2. V. N. Tsytovich:Sov. Phys. JETP,15, 320 (1962);Sov. Phys. Dokl.,7, 411 (1962);Sov. Phys. JETP,16, 1260 (1963).
3. G. B. Zhdanov, M. I. Tretyakova, V. N. Tsytovich andM. V., Sherbakova:Sov. Phys. JETP,16, 245 (1963).
4. K. I. Alekseeva, G. B. Zhdanov, M. I. Tretyakova andM. V. Sherbakova:Sov. Phys. JETP,17, 1254 (1963).
5. F. R. Buskirk, J. N. Dyer, H. D. Hanson, R. Seng andR. H. Weidman:V Int. Conf. on Nuclear Phot., CERN Geneva 1964, CERN 65-4, Vol. II, IX-9.