COMMISSION ISSN 0014-2352 OF THE EUROPEAN COMMUNITIES GURO ABSTRACTS Scientific and technical publications from Community-funded research and development VOL. 28 N° 9/1990 ABSTRACTS : PUBLICATIONS 28/801-28/900 EURO ABSTRACTS is compiled by the Commission of the European Communities DGXIII 'Telecommunications, Information Industries and Innovation' and published by the Office for Official Publications of the European Communities in association with ECOTEC Research and Consulting Ltd EABS, the on-line version of Euroabstracts, is accessible free of charge through ECHO (European Commission Host Organization) For Information, please contact : ECHO Support ; 177, route d'Esch ; L-1471 LUXEMBOURG EURO ABSTRACTS The abstracting journal of scientific and technical publications of the Commission of the European Communities Vol. 28 September 1990, N° 9 COMMENT AVAILABILITY BEZUGSQUELLEN SE PROCURER LES DOCUMENTS Publications Veröffentlichungen Publications Diese umfassen Berichte. Vorträge und Artikel, These comprise reports, papers and articles Par publications, on entend les rapports, exposés covering the scientific and technical programme die im Rahmen des wissenschaftlichtechnis oraux et articles issues du programme scientiof the European Communities. The addresses chen Programms der Europaischen Gemeinschaf fique et technique des Communautés européenwhere full texts may be ordered are indicated by ten erstellt wurden.