@article{AMLG_1977__18_137928,
     author = {Klaus Potthoff},
     title = {A simple tree and its application to a counterexample of {Philips.}},
     journal = {Archiv f\"ur mathematische Logik und Grundlagenforschung},
     pages = {67--72},
     publisher = {mathdoc},
     volume = {18},
     year = {1977},
     zbl = {0402.03024},
     url = {http://geodesic.mathdoc.fr/item/AMLG_1977__18_137928/}
}