AGNARSSON ULFUR 549,854 CLAYDEN GRAHAM, AGNARSSON ULFUR Constipation in childhood /Graham Clayden and Ulfur Agnarsson. - Oxford [etc.] : Oxford University Press, 1991. - VIII, 123 s. : il., wykr. ; 24 cm ISBN 0-19-262044-4 ISBN 0-19-262027-4