@article{AMLG_1978__19_137943,
     author = {R. Haberth\"ur},
     title = {Choice sequences and reduction processes.},
     journal = {Archiv f\"ur mathematische Logik und Grundlagenforschung},
     pages = {31--50},
     publisher = {mathdoc},
     volume = {19},
     year = {1978},
     zbl = {0404.03046},
     url = {http://geodesic.mathdoc.fr/item/AMLG_1978__19_137943/}
}