1. Rahman M. M., Ibrahim T. K., Kadirgama K., Mamat R. and Bakar R. A., presented at the Adv. Mat. Res., (2011) (unpublished).
2. Ibrahim T. K., Rahman M. and Sharma K., presented at the International Conference on Mechanical and Electrical Technology, 3rd,(ICMET-China 2011), Volumes 1-3, (2011) (unpublished).