@article{10_37236_6507,
     author = {Alex Cameron},
     title = {Extremal numbers for directed hypergraphs with two edges},
     journal = {The electronic journal of combinatorics},
     year = {2018},
     volume = {25},
     number = {1},
     doi = {10.37236/6507},
     zbl = {1392.05048},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/6507/}
}