@article{10_4064_cm_13_2_217_221,
     author = {Helen F. Cullen},
     title = {Curve breakers},
     journal = {Colloquium Mathematicum},
     pages = {217--221},
     publisher = {mathdoc},
     volume = {13},
     number = {2},
     year = {1964},
     doi = {10.4064/cm-13-2-217-221},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-13-2-217-221/}
}