@article{GDZPPN002083248, title = {The Magic World of Geometry - I. The Isoperimetric Problem.}, journal = {Elemente der Mathematik}, volume = {49}, year = {1994}, pages = {61-65}, zbl = {0812.52004}, url = {http://dml.mathdoc.fr/item/GDZPPN002083248} }
Hansen, Vagn Lundsgaard. The Magic World of Geometry - I. The Isoperimetric Problem.. Elemente der Mathematik, Tome 49 (1994) pp. 61-65. http://gdmltest.u-ga.fr/item/GDZPPN002083248/