Moosaei, Hossein, et al. “Exact Solutions to the Perturbed Nonlinear Schrödinger’s Equation With Kerr Law Nonlinearity by Using the First Integral Method”. Nonlinear Analysis: Modelling and Control, vol. 16, no. 3, July 2011, pp. 332-9, https://doi.org/10.15388/NA.16.3.14096.