@article{CMUC_1966_7_3_a13,
     author = {Hedrl{\'\i}n, Zden\v{e}k and Vop\v{e}nka, Petr},
     title = {An undecidable theorem concerning full embeddings into categories of algebras},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {401--409},
     year = {1966},
     volume = {7},
     number = {3},
     mrnumber = {0202798},
     zbl = {0149.25203},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1966_7_3_a13/}
}