@article{NSJOM_1989_19_2a_5,
     author = {Petrovi\'c Vojislav},
     title = {On unavoidable subgraphs 

 of strong tournaments},
     journal = {Novi Sad Journal of Mathematics},
     pages = {61-66},
     publisher = {mathdoc},
     volume = {19},
     number = {2},
     year = {1989},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_1989_19_2a_5/}
}