@article{CMUC_1974__15_1_a9,
     author = {Williams, James},
     title = {On a question of {Pultr} regarding categories of structures},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {113--126},
     publisher = {mathdoc},
     volume = {15},
     number = {1},
     year = {1974},
     mrnumber = {0360738},
     zbl = {0279.18003},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1974__15_1_a9/}
}