@article{CMUC_1981_22_3_a12,
     author = {H\'ajek, Petr},
     title = {Completion closed algebras and models of {Peano} arithmetic},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {585--594},
     year = {1981},
     volume = {22},
     number = {3},
     mrnumber = {633586},
     zbl = {0499.03022},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1981_22_3_a12/}
}