@article{AM2_1976__14_136596,
     author = {R.N., Haff, C.E. Burns},
     title = {A combinatorial ranking problem.},
     journal = {Aequationes mathematicae},
     pages = {351--356},
     publisher = {mathdoc},
     volume = {14},
     year = {1976},
     zbl = {0327.05122},
     url = {http://geodesic.mathdoc.fr/item/AM2_1976__14_136596/}
}