@article{CMUC_1983_24_4_a7,
     author = {Pudl\'ak, Pavel},
     title = {A definition of exponentiation by a bounded arithmetical formula},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {667--671},
     year = {1983},
     volume = {24},
     number = {4},
     mrnumber = {738562},
     zbl = {0533.03032},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1983_24_4_a7/}
}