Ron,
The Steel Construction Manual tables 8-4 thru 8-11 use the instantaneous center of rotation method (plastic). I only recall seeing the elastic method in Blodgett's book. While it is fairly easy to use hand calculation for the elastic method; tables, a spreadsheet or other software is probalably more practical for the instantaneous center of rotation method. The only example calculations for the instaneous center of rotation method that I have found is in Salmon and Johnson's text. I would like to see other examples if anyone knows of any.