Doctoral thesis (2003) - TE Motoasca (author) , H. Blok (promotor) , Peter M. Van Den Berg (copromotor) , M.D. Verweij (copromotor) , JJ Smit (copromotor) , R van Keer (copromotor) , BP de Hon (copromotor) , WC Emmens (copromotor) , Braham Ferreira (copromotor)