1. 3) H. OKADA, K. YUKAWA, and H. TAMURA : Corrosion, 30 (1974), p. 253 ; Corrosion, 32 (1976), p. 201
2. 4) Y. MONDEN, T. TAMURA, and J. NAGUMO : Proc. 4th Intern. AE Symp. (1978), Tokyo, 6-1
3. 5) C. E. HARTBOWER, W. G. REUTER, C. F. MARAIS, and P. P. CRIMINS : ASTM, STP, 505 (1972), p. 187
4. 6) H. L. DUNEGAN and D. O. HARRIS : Experimental Technique of Fracture Mechanics, "AE Techniques", p. 38, [The Iowa State University Press, Society for Experimental Stress Analysis, Westport, Conneticut]
5. 7) N. J. MAGNANI : Expl. Mec., December (1973), p. 526