@article{MM2_1977__21_154467,
     author = {Hans Wilhelm Alt},
     title = {The {Fluid} {Flow} {Through} {Porous} {Media.} {Regularity} of the {Free} {Surface.}},
     journal = {Manuscripta mathematica},
     pages = {255--272},
     publisher = {mathdoc},
     volume = {21},
     year = {1977},
     zbl = {0371.76080},
     url = {http://geodesic.mathdoc.fr/item/MM2_1977__21_154467/}
}