J.H. Potgieter, S.S. Potgieter- Vermaak, D.D. Tona, L. Anelich, M.P. Roux and W. Delport
Journal of Applied Sciences 4 ( 2 ): 313 - 316 , 2004
S. Bakovic, J.H. Potgieter, D. deWaal and L. Popovic
Journal of Applied Sciences 6 ( 5 ): 1009 - 1016 , 2006