SamoilenkoV. G., & SamoilenkoY. I. (2018). Asymptotic $Σ$-solutions to singularly perturbed Benjamin – Bona – Mahony equation with variable coefficients. Ukrains’kyi Matematychnyi Zhurnal, 70(2), 236-254. Retrieved from http://umj.imath.kiev.ua/index.php/umj/article/view/1554