@article{MZ_1967__99_170760,
     author = {Matthew I. Gould and George Gr\"atzer},
     title = {Boolean {Extensions} and {Normal} {Subdirect} {Powers} of {Finite} {Universal} {Algebras.}},
     journal = {Mathematische Zeitschrift},
     pages = {16--25},
     publisher = {mathdoc},
     volume = {99},
     year = {1967},
     zbl = {0153.33901},
     url = {http://geodesic.mathdoc.fr/item/MZ_1967__99_170760/}
}