https://collections.arolsen-archives.org/en/search/topic/6-3-3-2_06030302-0-706-533?s=Oster%20Martha
Gedenkbuch - Memorial book entry (bundesarchiv.de)
Holocaust Survivors and Victims Database – Martha OSTER (ushmm.org)
Marta Oster (yadvashem.org)
Martha Elisabeth Oster (yadvashem.org)
Martha Elisabeth Oster (Abraham) (1879 - 1941) - Genealogy (geni.com)
Martha Abraham
https://www.mappingthelives.org/bio/479f09ab-0659-4cc1-9645-12cd36a261fb
https://www.alemannia-judaica.de/bruttig_synagoge.htm