@article{GDZPPN002085860, title = {The tightness of tubes.}, journal = {Forum mathematicum}, volume = {9}, year = {1997}, pages = {707-720}, zbl = {0885.53065}, url = {http://dml.mathdoc.fr/item/GDZPPN002085860} }
Kühnel, Wolfgang; Breuer, Peter. The tightness of tubes.. Forum mathematicum, Tome 9 (1997) pp. 707-720. http://gdmltest.u-ga.fr/item/GDZPPN002085860/