@article{10_1017_S0017089500000914,
     author = {Wright, E. M.},
     title = {The number of irreducible tournaments},
     journal = {Glasgow mathematical journal},
     pages = {97--101},
     year = {1970},
     volume = {11},
     number = {2},
     doi = {10.1017/S0017089500000914},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500000914/}
}