- document
- De Veer, J.D. (author) doctoral thesis 1966
- document
- Walther, A. (author) doctoral thesis 1959
- document
- Brouwer, W. (author) doctoral thesis 1957
- document
- Selling, H.J. (author) doctoral thesis 1949
- document
- Hekker, F. (author) doctoral thesis 1947
- document
- Stephan, W.G. (author) doctoral thesis 1947