Ndebeka, W. I.
Neethling, P. H.
Rohwer, E. G.
Steenkamp, C. M.
Bergmann, J.
Stafast, H.
Funding for this research was provided by:
Thüringer Ministerium für Bildung, Wissenschaft und Kultur
African Laser Centre, Council for Scientific and Industrial Research
Council for Scientific and Industrial Research