@article{10_37236_1020,
     author = {Peter Hamburger and Penny Haxell and Alexandr Kostochka},
     title = {On directed triangles in digraphs},
     journal = {The electronic journal of combinatorics},
     year = {2007},
     volume = {14},
     doi = {10.37236/1020},
     zbl = {1157.05311},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/1020/}
}