1. Das semantische System der deutschen Modalverba;Bech;Travaux du cercle linguistique de Copenhague,1949
2. Will and be going to;Binnick,1971
3. Will and be going to II;Binnick,1972
4. The semantics of the modal auxiliaries in contemporary German;Bouma,1973
5. Jakobson's view of grammatical meaning;Bouma,1974