Book References:

1. Paula, Peter Atkins, Julio de (2009). Elements of physical chemistry (5th ed. ed.). Oxford: Oxford U.P
2. Brian C Smith (1995). Fundamentals of Fourier Transform Infrared Spectroscopy, Donald L. Pavia Gary M. Lampman, George S. Kriz James A. Vyvyan (2008) Introduction to Spectroscopy. Brooks/Cole
3. Colin N. Banwell, Elaine M. McCash (1994). Fundamentals of Molecular Spectroscopy. Mcgraw hill.

Web references:

1. Spectral Mode Identification

2. Problems on Spectroscopy