Distributors:

for the United States and Canada Kluwer Boston, Inc. 190 Old Derby Street Hingham, MA 02043 USA for all other countries Kluwer Academic Publishers Group Distribution Center P.O. Box 322 3300 AH Dordrecht The Netherlands

Library of Congress Cataloging in Publication Data

ISBN 90-6021-471-4 (this volume) ISBN 90-6021-460-9 (series)

Copyright © 1980 Bibliotheca Universitatis Leidensis All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, mechanical, photocopying, recording, or other wise, without the prior written permission of the publisher. Martinus Nijhoff Publishers bv. P.O. Box 566. 2501 CN The Hague, The Netherlands. PRINTED IN THE NETHERLANDS