I just took a gander for the AISC publication... and the errata for it is pretty comprehensive. It might be a good place to start... other than the CISC manual (I don't know if you have access to the Canadian pub...
One very good resource is Design of Welded Structures by Blodgett. It is published by the Lincoln Weld Society or something, but it is very inexpensive about $25, and has a lot of information.I would recommend it for any steel designer
who manufacture cell beams by cutting rolled I sections long the web with a pattern and then weld the two halves back together to create a deeper beam with openings in the web (
They have free software also which will design to both to BS5950 and EC3.
The output from the software should be able to help you see the design process.
As for a reference SCI Publication 100 - Design of composite and non-composite cellular beams is good. (