@article{MZ_1968__108_171086,
     author = {A. Almeida Costa},
     title = {Sur les {\textmu}-demi-anneaux.},
     journal = {Mathematische Zeitschrift},
     pages = {10--14},
     publisher = {mathdoc},
     volume = {108},
     year = {1968},
     zbl = {0167.30501},
     url = {http://geodesic.mathdoc.fr/item/MZ_1968__108_171086/}
}