@article{10_4064_cm91_1_6,
     author = {Konrad Pi\'oro},
     title = {$n${-Functional} digraphs
uniquely determined by the skeleton},
     journal = {Colloquium Mathematicum},
     pages = {79--89},
     publisher = {mathdoc},
     volume = {91},
     number = {1},
     year = {2002},
     doi = {10.4064/cm91-1-6},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm91-1-6/}
}