@article{AM2_1980__20_182378,
     author = {Robert M. Tardiff},
     title = {On a functional inequality arising in the construction of the product of several metric spaces.},
     journal = {Aequationes mathematicae},
     pages = {51--58},
     publisher = {mathdoc},
     volume = {20},
     year = {1980},
     zbl = {0432.39010},
     url = {http://geodesic.mathdoc.fr/item/AM2_1980__20_182378/}
}