@article{MZ_1991__206_1_174231,
     author = {Richard K. Skora},
     title = {Knot and link projections in 3-manifolds.},
     journal = {Mathematische Zeitschrift},
     pages = {345--350},
     publisher = {mathdoc},
     volume = {206},
     number = {1},
     year = {1991},
     zbl = {0695.57006},
     url = {http://geodesic.mathdoc.fr/item/MZ_1991__206_1_174231/}
}