@article{GDZPPN002043890,
title = {A classification of the ordinal recursive functions.},
journal = {Archiv f\"ur mathematische Logik und Grundlagenforschung},
volume = {13},
year = {1970},
pages = {136-153},
zbl = {0228.02027},
url = {http://dml.mathdoc.fr/item/GDZPPN002043890}
}
Wainer, S.S. A classification of the ordinal recursive functions.. Archiv für mathematische Logik und Grundlagenforschung, Tome 13 (1970) pp. 136-153. http://gdmltest.u-ga.fr/item/GDZPPN002043890/