D&D 3.5 - Underdark HC

This book was written by Bruce R. Cordell, Gwendolyn F.M. Kestrel, and Jeff Quick, and was released in October 2003 published by Wizards of the Coast.^[2] Cover art was by Sam Wood, with interior art by Kalman Andrasofszky, Matt Cavotta, Mike Dubisch, Wayne England, Matt Faulkner, Vance Kovacs, Vince Locke, Raven Mimura,Jim Pavelec, Vinod Rams, Richard Sardinha, Stephen Tappin, and Joel Thomas.

When asked how the designers dealt sorting through years' worth of publications on the Underdark to create a more definitve sourcebook, Jeff Quick responded: "I was the editor of Eric Boyd's exhaustively detailed 2nd edition sourcebook, Drizzt Do'Urden's Guide to the Underdark. Eric, as Forgotten Realms fans know, is a detail nut. When he wrote it, he consulted pretty much every Underdark reference ever -- including Bob Salvatore, personally. So rather than duplicate effort, I turned to that book for inspiration and to Eric for a few details and opinions."

-Wikipedia