1. K. Ramya, N.T. Saraswathi, C.R. Raja, Growth and characterization of an organic nonlinear optical material: L-Histidine malonate,Opt. Laser Technol. 84 (2016) 102–106.
2. Growth and characterization of l-Histidinium chloroacetate (LHCA): a new nonlinear optical material;Paul Chinnappan;Optik. (Stuttg),2016
3. Introduction to Nonlinear Optical Effects in Molecules and Polymers;Prasad,1991
4. Nonlinear Optical Properties of Organic Molecules and Crystals;Chemla,1987
5. V. Degiorgio, C. Flytzanis, Proc. Of the International School of Physics “Enrico Fermi” 126 1995.