@article{KYB_1973_9_2_a0,
     author = {Nebesk\'y, Ladislav},
     title = {An outerplanar test of linguistic projectivity},
     journal = {Kybernetika},
     pages = {81--83},
     year = {1973},
     volume = {9},
     number = {2},
     mrnumber = {0451893},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/KYB_1973_9_2_a0/}
}