@article{NUMA_1980__36_132691,
     author = {H.W. Alt},
     title = {Numerical {Solution} of {Steady-State} {Porous} {Flow} {Free} {Boundary} {Problems.}},
     journal = {Numerische Mathematik},
     pages = {73--98},
     publisher = {mathdoc},
     volume = {36},
     year = {1980},
     zbl = {0447.76074},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1980__36_132691/}
}