@article{GDZPPN002043009,
title = {On the universal completeness of classes of relational systems.},
journal = {Archiv f\"ur mathematische Logik und Grundlagenforschung},
volume = {5},
year = {1960},
pages = {90-95},
zbl = {0121.01204},
url = {http://dml.mathdoc.fr/item/GDZPPN002043009}
}
Ribeiro, Hugo. On the universal completeness of classes of relational systems.. Archiv für mathematische Logik und Grundlagenforschung, Tome 5 (1960) pp. 90-95. http://gdmltest.u-ga.fr/item/GDZPPN002043009/