00392nam a2200133Ia 4500082001900000100002400019245004600043250000800089260002600097300002900123500009600152500000500248700000500253  a530.1bL252.VP  aLanczos, Cornelius.  aThe variational principles of mechanicsb  a4th  aNew YorkbDoverc1986  axxix, 418p. Index, Bibl.  a"Unabridged republication of the 4th ed. published by Univ. of Toronto Pr., Toronto, 1970".  a  a