1. Berendsohn, W. G., 1994: IOPI World Vascular Plant Checklist. A CASE model of checklist system data. ? InWilson, K., (Ed.): Global Plant Checklist project plan, Appendix 4. ? Sidney: International Organization for Plant Information (IOPI). (Unpubl. mimeography updated version available via the IOPI World Wide Web server on the Internet or as hardcopy from the author.)
2. ?, 1995: The concept of ?potential taxa? in databases. ? Taxon44: 207?212.
3. ?, Anagnostopoulos, A., Hagedorn, G., Jakupovic, J., Nimis, P. L., Valdés, B., 1997: The CDEFD information model for biological collections. ? In: Proc. ESF workshop ?Disseminating Biodiversity Information?, Amsterdam, March 24?27, 1996. ? Strasbourg: European Science Foundation (in press).
4. ?, Jakupovic, J., Nimis, P. L., Valdés, B., 1996: An introduction to the CDEFD Information Model. ? In: Proc. 8th OPTIMA meeting. ? Lagascalia18: 567?571.
5. Battaglia, E., 1957: A simplified Feulgen method using cold hydrolysis. ? Caryologia9: 372?373.