1. The First Fifteen years;Jennings;IDR,1995
2. E.-G Ng, D.K. Aspinwall, Evaluation of cutting force and temperature when turning hardened die steel with AMBORITE AMB90 and DCB50 tooling. 59 (582) 183–240.
3. Specialty Steels and Hard Materials.;Exner,1983
4. O. Toll wear and cutting temperature of cBN tools of machining of hardened steels;Norihiko;CIRP Ann.,1979
5. Amborite- a remarkable new cutting material from de Beers;Pipkin;IDR,1980