Citation Hunt

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page Zuiderzee:

"

Contained within the Zuiderzee were five small islands,[1] the remains of what were once larger islands, peninsulas connected to the mainland, or in the case of Pampus, an artificial island.[citation needed] These were Wieringen, Urk, Schokland, Pampus and Marken.[1] The inhabitants of these islands also subsisted mainly on fishing and related industries and still do in the case of Urk and Wieringen. All of these islands, except for Pampus, are now part of the mainland or connected to it.[citation needed]