2) R. A. SWIFT and H. C. ROGERS : Welding J. Research Supplement, 52 (1973), p. 145s
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 )