1. Location of free surface in porous media;Liggett;J. Hydraul. Div. Amer. Soc. Civil Eng.,1977
2. Liggett , J. A. P. L.-F. Liu Unsteady free surface flow through a zoned dam using boundary integration Proceedings of the Symposium on Applications of Computer Methods 357 365 Los Angeles 1977
3. Liu , P. L.-F. J. A. Liggett Boundary integral solutions to groundwater problems Proceedings of the First International Conference on Applied Numerical Modelling 559 569 Southampton, England 1977