(2/2) GlobalSecurity.org datasheet about the Ula class Ula model boat dead link Nordseewerke's page about the Ula class Østlandets Blad, "Fire dager i dypet" Dagbladet articles about the class: "Oppdaterer ubåtene" "Her tar den norske ubåten smuglerskipene" "Hestehviskerne" Submarine classes Ships built in Emden Submarines of Germany