https://www.joodsmonument.nl/en/page/152225/walter-klein
https://www.mappingthelives.org/bio/9100d2b8-89b3-4522-aa56-1f5298c663d9
https://archief.amsterdam/indexen/deeds/98517a9c-6542-3112-e053-b784100aeeb7?person=98517a9c-6543-3112-e053-b784100aeeb7
#typo #geo POR: [Roerstraat]