Kholyavka, O. T. “Hyperbolic Variational Inequality of the Third Order With Variable Exponent of Nonlinearity”.
Ukrains’kyi Matematychnyi Zhurnal
, vol. 66, no. 4, Apr. 2014, pp. 518–530,
https://umj.imath.kiev.ua/index.php/umj/article/view/2154
.