@article{AMLG_1981__21_137982,
     author = {Hans Kleine B\"uning},
     title = {Some undecidable theories with monadic predicates and without equality.},
     journal = {Archiv f\"ur mathematische Logik und Grundlagenforschung},
     pages = {137--148},
     publisher = {mathdoc},
     volume = {21},
     year = {1981},
     zbl = {0475.03022},
     url = {http://geodesic.mathdoc.fr/item/AMLG_1981__21_137982/}
}