@article{10_37236_1667,
     author = {Jian Shen and Raphael Yuster},
     title = {A note on the number of edges guaranteeing a {\(C_4\)} in {Eulerian} bipartite digraphs},
     journal = {The electronic journal of combinatorics},
     year = {2002},
     volume = {9},
     doi = {10.37236/1667},
     zbl = {0994.05070},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/1667/}
}