http://www.archive.org/search.php?query=subject:"Ruhleben (Concentration camp)" http://www.archive.org/details/germanprisonersi00bolt http://www.archive.org/details/ofmainprisoncmap00poperich http://www.archive.org/details/myexperiencesasg00austuoft http://www.archive.org/details/reportsonbritish00inteuoft http://www.archive.org/details/turkishprisoners00inte