@article{10_4064_cm_52_1_1_22,
     author = {J\"urg Schmid and J\"urgen Schmidt},
     title = {Enlargements without urelements},
     journal = {Colloquium Mathematicum},
     pages = {1--22},
     publisher = {mathdoc},
     volume = {52},
     number = {1},
     year = {1987},
     doi = {10.4064/cm-52-1-1-22},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-52-1-1-22/}
}