[pdf] The Rock Physics Handbook: Tools for Seismic Analysis in Porous Media Gary Mavko, Tapan Mukerji, Jack Dvorkin

Excellent reference. Improvements would be more explanation of the variables in the equations. The index at the back is off, for example a reference on page 60 (Greenberg et al)is actually on page 64 and another topic that is supposed to be on page 235 is actually on page 246 (Smith and Gidlow).