The AISI "Cold-Formed Steel Framing Design Guide" is pretty good, but you need to have the AISI Cold-Formed Steel Design Manual as a companion (or vice-versa). I have a 1962 copy of the Design Manual and a 2001 copy of the Design Guide; the former has lots of neat derivation of moment of inertia of lines... That, I'm pretty sure, are also provided in Blodget's Design of Weldments.