00460nam a2200109Ia 4500008004100000082001900041100002100060245006900081260003800150300002600188500013600214251030b        |||||||| |||| 00| 0 eng d  a515.9bC858.DP  aCourant, Richard  aDirichlet's principle, conformal mapping and minimal surfacesb/  aNew York:bSpringer-Verlag,c1977  axi, 332p. Bibl. Index  a"It expresses the balance and tension between the individuality of mathematical objects and the generality of mathematical methods"