@article{JGAA_2020_24_3_a7,
     author = {Daniel Gon\c{c}alves},
     title = {Not all planar graphs are in {PURE-4-DIR}},
     journal = {Journal of Graph Algorithms and Applications},
     pages = {293--301},
     publisher = {mathdoc},
     volume = {24},
     number = {3},
     year = {2020},
     doi = {10.7155/jgaa.00533},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.7155/jgaa.00533/}
}