- K. H. Karlsen, K. A. Lie, N. H. Risebro, J. Fr\o yen. A front tracking approach to a two phase fluid-flow model with capillary forces. IN SITU, 22:55-89, 1998.
- R. M. Colombo, N. H. Risebro. Continuous dependence in the large for some equations of gas dynamics. Comm. Partial Differential Equations, 23:1693-1718, 1998.
- S. Evje, K. H. Karlsen, K. A. Lie, N. H. Risebro. Front tracking and operator splitting for nonlinear degenerate convection diffusion equations. In Proceedings from the IMA workshop on parallell algorithms for PDEs, 1998.