1. Lillie, M. C. Cranial surgery dates back to Mesolithic. Nature 391, 854 (1998).
2. Alt, K. W. et al. Evidence for Stone Age cranial surgery. Nature 387, 364 (1997).
3. Crubézy, E. et al. The antiquity of cranial surgery in Europe and in the Mediterranean basin. C. R. Acad. Sc. Paris 332, 417–423 (2001).
4. Margetts, E. Trepanation of the skull by the medicine-men of primitive cultures, with particular reference to present-day native East African practice. In Diseases in Antiquity (Brothwell, D. & Sandison, A. T. eds), Charles C. Thomas, Springfield, IL, pp. 673–701 (1967).
5. Houghton, P. Trephination in Oceania. J. Polynesian Soc. 8, 265–269 (1977).