@article{700131,
     title = {Free boundary problems for Stoke's flows and finite element methods},
     booktitle = {Equadiff 6},
     series = {GDML\_Books},
     publisher = {J. E. Purkyn\v e University, Department of Mathematics},
     address = {Brno},
     year = {1986},
     pages = {[327]-332},
     mrnumber = {MR0877144},
     zbl = {0617.76033},
     url = {http://dml.mathdoc.fr/item/700131}
}

Nitsche, Joachim A. Free boundary problems for Stoke's flows and finite element methods, dans Equadiff 6, GDML_Books,  (1986), pp. [327]-332. http://gdmltest.u-ga.fr/item/700131/