[1]
BarannykT.A., BarannykA.F. and YurykI.I. 2017. Exact solutions of the nonliear equation $u_{tt} = = a(t) uu_{xx} + b(t) u_x^2 + c(t) u $. Ukrains’kyi Matematychnyi Zhurnal. 69, 9 (Sep. 2017), 1180-1186.