2
by Wolf, Norbert
Published 1997
Centaurus Verlag & Media

3
by Coombes, Hilary
Published 2001
Macmillan Education UK

4
by Morris, Noel M.
Published 1996
Macmillan Education UK

10
Published 1997
Springer Netherlands

12
Published 1989
Springer Netherlands

13
by Bowman, M.J.
Published 1981
Springer Netherlands

15
Published 1983
Springer Netherlands

16
by Vithal, Renuka
Published 2003
Springer Netherlands

17
by Freudenthal, Hans
Published 1973
Springer Netherlands

18
Published 2001
Springer Netherlands

19
by Reuchlin, M.
Published 1972
Springer Netherlands

20
Published 1995
Springer Netherlands