1. J. R. Fisher,Gold Bull, 1976,9, (2), 58–63
2. P. M. Roberts,Gold Bull, 1973,6, (4), 112–119
3. D. T. Easby,Univ. Mus. Bull. Univ. Pennsylvania, 1965,5, (4), 3–15
4. H. N. Lechtman, in ‘Science and Archaeology’ ed. by R. H. Brill, M.I.T. Press, Cambridge, Mass., 1971, 2–30 and in ‘Application of Science in Examination of Works of Art’, ed. by W. J. Young, Museum of Fine Arts, Boston, Mass., 1973, 38–52
5. C. Donnan,Archaeol., 1973,26, (4), 289–297