Bathe, K.J., "Finite Element Procedures", 1996 [STI: very good intro FEA book, has good intro section on nonlinearities as well.]
Cook, R.D., Malkus, D.S., Plesha, M.E., "Concepts and Applications of Finite Element Analysis", 3rd ed, 1989 [STI: good intro FEA book, easier reading than Bathe.]
Patankar, S.V., "Numerical Heat Transfer and Fluid Flow", 1980 [STI: very good text on CFD and heat transfer, finite difference methods]
Crisfield, M.A., "Non-linear Finite Element Analysis of Solids and Structures", Vol. 1, 1991 and Vol. 2, 1997 [STI: very good text on structural nonlinearities]
Belytschko, T., Liu W.K., Moran B., "Nonlinear Finite Elements for Continua and Structures", 2000
Kinsler, L.E., Frey, A.R., Coppens, A.B., Sanders, J.V., "Fundamentals of Acoustics", 3rd ed., 1982 [STI: good intro text on acoustics]
Pierce, A.D., "Acoustics: An Introduction to Its Physical Principles and Applications", 1991 [STI: good intro text on acoustics]
Morse, P.M., Ingard, K.U., "Theoretical Acoustics", 1968 [STI: very good overall text on acoustics; for me, it's a bit tough but very worthwhile reading]
Christiansen, D., "Electronics Engineers' Handbook", 4th ed., 1996 [STI: good, thorough text. Can think of it as a "Mark's Handbook" for Electronics]
Steinberg, D.S., "Cooling Techniques for Electronic Equipment", 2nd ed., 1991 [STI: A must for electronics packaging, thermal issues]
Steinberg, D.S., "Vibration Analysis for Electronic Equipment", 2nd ed., 1988 [STI: A must for electronics packaging, structural issues, mainly related for military applications -- shock & vibe, etc.]