Page 68 - Textos de Matemática Vol. 43
P. 68
56 ANNA KOROLKO AND IRINA MARKINA
(A. Korolko) Mathematical Institute University of Bergen
Norway
E-mail address: anna.korolko@uib.no
(I. Markina) Mathematical Institute University of Bergen
Norway
E-mail address: irina.markina@uib.no
