Raju, T. S., & Kumar, C. N. (2016). Unbreakable PT symmetry of exact solitons in nonlinear optical media with higher-order diffraction. 13th International Conference on Fibre Optics and Photonics, Kanpur, India. 4-8 December 2016. DOI: 10.1364/PHOTONICS.2016.Th3A.26