Amberweb: a project for an Internet centre on amber artefacts, the logical structure of the data-bank and the implementation of new data in the archaeological sector - Negroni Catacchio, Nuccia (Investigations into amber. Badania bursztynu. Proceedings of the International Interdisciplinary Symposium: Baltic amber and other fossil resins. 997 Urbs Gyddanycz-1997 Gdańsk. Gdańsk, 2-6 september 1997., 1999)