1. Abraham, Werner: 1976, ?noch and schon als polare Satzfunktoren?, in K. Sprengel, W.-D. Bald, and H. W. Viethen (eds.):Semantik and Pragmatik, Niemeyer, Tübingen, pp. 3?20.
2. Abraham, Werner: 1980, ?The Synchronic and Diachronic Semantics of German Temporal noch and schon, with Aspects of English Still, Yet, and Already?,Studies in Language 4(1),3?24.
3. Bäuerle, Rainer: 1979,Temporale Deixis, Temporale Frage, Gunter Narr, Tübingen.
4. Comrie, Bernard: 1976,Aspect, Cambridge University Press, Cambridge.
5. Comrie, Bernard: 1985,Tense, Cambridge University Press, Cambridge.