There was a contribution in the October 1996 issue of the ESA Bulletin (p. 219 f) on how to determine the order and inclusion of authors. I am putting it on my web server for a few weeks, so you can have a look at it (http://martinkoechy.de/research/authorship.pdf).
-- Martin Köchy (Koechy), PhD Telefon: +49-331-977 1974 Fax: +49-331-977 1948 AG Vegetationsökologie & Naturschutz [ http://home.wtal.de/koechy/AG/ ] (RG Vegetation Ecology & Nature Conservation) Maulbeerallee 3 * Universität Potsdam * Postfach 60 15 53 * 14415 Potsdam * GERMANY/ALLEMAGNE == Please don't send me Word or PowerPoint attachments if not absolutely necessary. Use RTF, HTML, or PDF. See: http://www.gnu.org/philosophy/no-word-attachments.html
