https://www.mappingthelives.org/bio/5f3f7eec-1acd-4377-b095-66e114cb3af7
https://www.stolpersteine-berlin.de/de/kantstr-120-121-kantstr/120-121/erna-ewer
http://www.fdrlibrary.marist.edu/_resources/images/wrb/wrb0593.pdf