@article{RCM_1993__27_1-2_181881,
     author = {Hernando Gait\'an},
     title = {Quasivarieties of {De} {Morgan} algebras},
     journal = {Revista colombiana de matematicas},
     pages = {203--208},
     publisher = {mathdoc},
     volume = {27},
     number = {1-2},
     year = {1993},
     zbl = {0801.06026},
     url = {http://geodesic.mathdoc.fr/item/RCM_1993__27_1-2_181881/}
}