Posashkov, Sergey, e V.A. Galaktionov. «Monotonicity in Time and Stationary Solutions for a Quasilinear Heat Equation with Source». Revista Matemática Complutense, vol. 4, n.º 2, janeiro de 1991, p. 251, https://doi.org/10.5209/rev_REMA.1991.v4.n2.17980.