1. 1) R. BRUSCATO : Welding Journal, 49 (1970) 4, p. 148 S
2. 2) R. A. SWIFT and H. C. ROGERS : Welding Journal, 52 (1973) 4, p. 145S
3. 3) C. D. CLAUSER, L. G. EMMER, A. W. PENSE and R. D. STOUT : Paper for presentation at a session on Refining Piping during the 37th Midyear Meeting of American Petroleum Institute (1972 5 fl 11 p )
4. 4) R. A. SWIFT and J. A. GULYA : Welding Journal, 52 (1973) 2, p. 57S
5. 5) K. MIYANO and T. ADACHI : Trans. ISIJ, 11 (1971) 1, p. 54