@article{AMLG_1982__22_137990,
     author = {S.O. Aanderaa and E. B\"orger},
     title = {Prefix classes of {Krom} formulae with identity.},
     journal = {Archiv f\"ur mathematische Logik und Grundlagenforschung},
     pages = {43--50},
     publisher = {mathdoc},
     volume = {22},
     year = {1982},
     zbl = {0494.03007},
     url = {http://geodesic.mathdoc.fr/item/AMLG_1982__22_137990/}
}