@article{10_4064_cm93_2_2,
     author = {Friedrich Wehrung},
     title = {Join-semilattices with two-dimensional congruence amalgamation},
     journal = {Colloquium Mathematicum},
     pages = {209--235},
     publisher = {mathdoc},
     volume = {93},
     number = {2},
     year = {2002},
     doi = {10.4064/cm93-2-2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm93-2-2/}
}