@article {1997, title = {Viscosity solutions and uniquenessfor systems of inhomogeneous balance laws}, journal = {Discrete Contin. Dynam. Systems 3 (1997), no. 4, 477--5}, number = {SISSA;67/95/M}, year = {1997}, publisher = {SISSA Library}, url = {http://hdl.handle.net/1963/969}, author = {Graziano Crasta and Benedetto Piccoli} }