1. 1. Smith, D. J., Fryer, J. & Camps, R. A. Ultramicroscopy 19, 279-298 (1986). 2/ Fryer, J. R. & Holland, F. M. Proc. R. Soc. A393, 353-369 (1984). 3. Baird, T., Gall, J. H., MacNicol, D. D., Mallinson, P. R. & Michie, C. R. J. chem. Soc. Chem. Commun. 1471 1(988). 4. Murata, Y., Baird, T. & Fryer, J. R. J. Microsc. 108, 261-275 (1976). 5. Bricogne, G. Acta crystallogr. A40, 410-445 (1984). 6. Bricogne, G. & Gilmore, C. J. Acta crystallogr. A46, 284-297 (1990). 7. Gilmore, C. J., Bricogne, G. & Bannister, C. Acta crystallogr. A46, 297-308 1(990). 8. Gilmore, C. J., Henderson, K. & Bricogne, G. Acta crystallogr. A47, 830-841 (1991). 9. Gilmore, C. J., Henderson, A. N. & Bricogne, G. Acta crystallogr. A47, 842-846 (1991). 10. Fryer, J. R., Cleaver, J. R. A. & Smith, D. J. lnst. Phys. Conf. Ser. 52, 287-290 (1980). 11. Wang, D. N., Hovmoller, S., Kihlborg, L. & Sundberg, M. Ultramicroscopy 25, 303-316 (1988). 12. O'Keefe, M. A., Fryer, J. R. & Smith, D. J. Acta crystallogr. A39, 838-847 (1983). 13. Dorset. D. L. Acta crystallogr. A47, 510-515 (1991). 14. Bricogne, G. in Crystallographic Computing 4 (eds Isaacs, N. W. & Taylor, M. R.) 60-79 (Clarendon, Oxford, 1991). 15. Bricogne, G. Acta crystallogr. A44, 517-545 (1988). 16. Bricogne, G. in Maximum Entropy in Action (eds Buck, B. & Macaulay, V. A.) 187-216 (Clarendon, Oxford, 1991). 17. Hauptman, H. & Karle, J. The Solution of the Phase Problem: I The Centrosymmetric Crystal, ACA Monogr. No. 3. (Polycrystal Book Service, Pittsburgh, 1953). 18. Klug, A. Acta crystallogr. 11, 515-543 (1958). 19. Giacovazzo, C. Direct Methods in Crystallography (Academic, London, 1980). 20. Khinchin, A. I. Mathematical Foundations of Statistical Mechanics (Dover, New York, 1949). 21. Daniels, H. E. Ann. math. Statist. 25, 631-650 (1954). 22. Gilmore, C. J. J. appl. Crystallogr. 17, 42-46 (1984).