Select "wrc" and search for the bulletin (this is the official website of the Welding Research Council).
WRC 107 and 297 are based on different methods of analysis. 297 considers the relative stiffness of the nozzle as well as the cylindrical shell (297 considers only cylinders attached to cylinders).
The bulletin 297 determines the stress at only 4 cardinal points at the nozzle-shell junction. The bulletin is based on the shell analysis method developed by Professor Charles Steel at University of California. He published the FAST2 computer program based on this analysis, this software was was used (in part) to determine the curves in the 297 bulletin. FAST2 will spit out the stresses at various distances from the junction and at intermediate angles, a lot more useful.
Some specialized FEA software provides an option for anlysis per WRC 297. If you have access to such software, don't bother with the 297 analysis, just use the FEA.
