"Eastern Flevoland" . . "Zuiderzee Enclosure Dam" . . "Zuiderzee Works" . "Zuiderzee Works" . "reclaiming land from the sea" . . "flood protection and land reclamation" . . . . "East Flevoland" . . . . . . "converted" . "was reclaimed" . . . . "1924" . . . . . . . . . "IJsselmeerpolders" .