00341nam a2200121Ia 4500082002000000100002000020245005600040260003100096300002000127490006200147500000500209700000500214  a515.64bF911.VP  aFriedman, Avner  aVariational principles and free boundary problemsb  aNew YorkbJohn Wileyc1982  aix, 710p. Index  aWiley Interscience series in Pure and Applied Mathematics  a  a