Rykov, Y.G. «On the Behaviour of Generalized Solutions to Genuinly Nonlinear First Order Equations for SmaIl and Large Values of Time». Revista Matemática Complutense 6, no. 1 (enero 1, 1993): 139. https://doi.org/10.5209/rev_REMA.1993.v6.n1.17860.