“…Thus, considering proper initial and boundary conditions, we have a strongly nonlinear problem with no common methods for solving it. As a special note, the existence of exponentially damped, self‐similar, and stationary solutions of some particular cases has been discussed by Herrmann et al, 6 Crump and Seinfeld, 7 Simons, 8 Alexandrov et al, 9 and Makoveeva et al 10 ; the global existence of solutions has been proved for a large class of data by Laurençot 11 ; self‐similar solutions and the behavior of solutions over long times have been investigated by Alyab'eva et al 12 and Alexandrov 13,14 …”