1. H. Ismail, Z. Ahmad, U.S. Ishiaku, Z.A. Mohd Ishak, Proceedings of the 7th Scientific Conference of the Electron Microscopy Society Malaysia, 27–28 November 1998, Ipoh, Malaysia, pp. 70–73.
2. Z. Ahmad, H. Ismail, U.S. Ishiaku, Z.A. Mohd Ishak, Proceedings of the Regional Conference on Polymeric Material, 10–11 November 1998, Penang, Malaysia, pp. 276–282.
3. The Chemistry and Physics of Rubber Like Substances;Bateman,1963