@article{10_21136_CMJ_1972_101106,
     author = {Zelinka, Bohdan},
     title = {Isotopy of digraphs},
     journal = {Czechoslovak Mathematical Journal},
     pages = {353--360},
     publisher = {mathdoc},
     volume = {22},
     number = {3},
     year = {1972},
     doi = {10.21136/CMJ.1972.101106},
     mrnumber = {0306037},
     zbl = {0239.05118},
     language = {en},
     url = {https://geodesic-test.mathdoc.fr/articles/10.21136/CMJ.1972.101106/}
}