@article{AM2_1978__18_136774,
     author = {Philip Calabrese},
     title = {The probability of the triangle inequality in probabilistic metric squares.},
     journal = {Aequationes mathematicae},
     pages = {187--205},
     publisher = {mathdoc},
     volume = {18},
     year = {1978},
     zbl = {0383.60012},
     url = {http://geodesic.mathdoc.fr/item/AM2_1978__18_136774/}
}