Abstract: Tropospheric chemistry and space observation: Advanced study course, Riom near Clermont-Ferrand, France, 21-31 July 1997: Proceedings (1998) pp. 171-182; ISBN 92-828-1906-X; CG-NA-17790-EN-C; Available from the DG XII Documentation Centre, European Commission, 200 rue de la Loi, B-1049 Bruxelles (BE), Fax: +32-2-2969823