1
by Coșeriu, Eugenio
Published 1975
Fink

2
by Hentschel, Gerd
Published 1986
Sagner

3
by Blümel, Wolfgang
Published 1982
Vandenhoeck & Ruprecht

4
by Gorup, Radmila J.
Published 1987
Sagner

5
by Lehfeldt, Werner
Published 1993
Sagner

6
by Hentschel, Gerd
Published 1993
Sagner