@article{GDZPPN002438550, title = {Knot and link projections in 3-manifolds.}, journal = {Mathematische Zeitschrift}, volume = {207}, year = {1991}, pages = {345-350}, zbl = {0695.57006}, url = {http://dml.mathdoc.fr/item/GDZPPN002438550} }
Skora, Richard K. Knot and link projections in 3-manifolds.. Mathematische Zeitschrift, Tome 207 (1991) pp. 345-350. http://gdmltest.u-ga.fr/item/GDZPPN002438550/