@article{GDZPPN002083345, title = {The Magic World of Geometry - III. The Dirac String Problem.}, journal = {Elemente der Mathematik}, volume = {49}, year = {1994}, pages = {149-154}, zbl = {0834.57007}, url = {http://dml.mathdoc.fr/item/GDZPPN002083345} }
Hansen, Vagn Lundsgaard. The Magic World of Geometry - III. The Dirac String Problem.. Elemente der Mathematik, Tome 49 (1994) pp. 149-154. http://gdmltest.u-ga.fr/item/GDZPPN002083345/