Mls, Jiri, and Leopold Herrmann. “Oscillations for an Equation Arising in Groundwater Flow With the Relaxation Time”. Mathematical Modelling and Analysis 16, no. 4 (November 22, 2011): 527-536. Accessed January 6, 2025. https://mla.vgtu.lt/index.php/MMA/article/view/5562.