@article{MZ_1971__120_171520,
     author = {Jean Doyen and Guy Valette},
     title = {On the {Number} of {Non} {Isomophic} {Steiner} {Triple} {Systems.}},
     journal = {Mathematische Zeitschrift},
     pages = {178--192},
     publisher = {mathdoc},
     volume = {120},
     year = {1971},
     zbl = {0203.30803},
     url = {http://geodesic.mathdoc.fr/item/MZ_1971__120_171520/}
}