1. Materials science of cemented carbides — an overview
2. U.K.R. Fischer, E.T. Hartzell, J.G.H. Akerman, US Patent 4,743,515 (May 10, 1988).
3. J.G.H. Akerman, U.K.R. Fischer, E.T. Hartzell, US Patent 5,279,901 (January 18, 1994).
4. U.K.R. Fischer, E.T. Hartzell, J.G.H. Akerman, US Patent 4,820,482 (April 11, 1989).
5. Rock tools leads the way in drilling