- document
- Hoekstra, A.J. (author) doctoral thesis 2000
- document
- Hoekstra, A. (author) doctoral thesis 1998
- document
- Hoekstra, H.D. (author) doctoral thesis 1997
- document
- Hoekstra, B. (author) doctoral thesis 1978
- document
- Hoekstra, W. (author) doctoral thesis 1969
- document
- Hoekstra, T. (author) doctoral thesis 1958