1. Diamond drilling handbook;Heinz,1985
2. Colling, W.D. Achieving optimum drill bit performance - A practical method with particular relevance to deep hole drilling. Huddy Diamond Crown Setting Company (Pty) Ltd. Unpublished report.
3. Machine Design;Black,1986
4. Machinery’s Handbook (1989). Industrial Press Inc, New York. 23 rd edition, second printing, pp 512-51, 365-377, 2202-2205.