@article{CMH_1973__48_139565,
     author = {David Frank},
     title = {The {Signature} {Defect} and the {Homotopy} of {BPL} and {PL/O}},
     journal = {Commentarii mathematici Helvetici},
     pages = {525--530},
     publisher = {mathdoc},
     volume = {48},
     year = {1973},
     zbl = {0279.57012},
     url = {http://geodesic.mathdoc.fr/item/CMH_1973__48_139565/}
}