@article{MZ_1962__79_170047,
     author = {R. Venkataraman and N. Sankaran},
     title = {A generalization of the ordered group of integers.},
     journal = {Mathematische Zeitschrift},
     pages = {21--31},
     publisher = {mathdoc},
     volume = {79},
     year = {1962},
     zbl = {0146.25802},
     url = {http://geodesic.mathdoc.fr/item/MZ_1962__79_170047/}
}