1. 1) R. BRUSCATO : Welding J., 49 (1970), p. 148s
2. 2) R. A. SWIFT and H. C. ROGERS : Welding J. Research Supplement, 52 (1973), 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 API", May, 11 ( 1972 )
4. 4) R. A. SWIFT and J. A. GULYA : Welding J. Research Supplement, 52 (1973), 2, p. 57s
5. 6) K. MIYANO : Paper for presentation of the API Task Group Meeting in Chicago, Feb. 20/21 (1974)