@article{MZ_1962__79_170046,
     author = {R. Venkataraman},
     title = {Symmetric ordered sets.},
     journal = {Mathematische Zeitschrift},
     pages = {10--20},
     publisher = {mathdoc},
     volume = {79},
     year = {1962},
     zbl = {0131.01204},
     url = {http://geodesic.mathdoc.fr/item/MZ_1962__79_170046/}
}