P. M. Anbarasan, P. S. Kumar, K. Vasudevan, R. Govindan, A. Prakasam, and M. Geetha, “Geometrical, electronic structure, nonlinear optical and spectroscopic investigations of 4-(phenylthio)phthalonitrile dye sensitizer for solar cells using quantum chemical calculations”, Eur. J. Chem., vol. 2, no. 2, pp. 206–213, Jun. 2011.