1. Khalid, S. A. in Chemistry and Taxonomy of the Rutales (eds Waterman, P. G. & Erundan, M. F.) Ch. 10 (Academic, New York, 1983).
2. Forbes, R. J. Studies in Ancient Technology 3, 22 (Brill, Leiden, 1993).
3. Rose, P. J. Egyptian Archaeol. 82, 19–22 (1996).
4. Anderson, K. B. & Winans, R. E. Anal. Chem. 63, 2901–2908 (1991).
5. Evershed, R. P., Jerman, K. & Eglinton, G. Nature 314, 528–530 (1985).