1. On another article it is said that Ephraim Kanarek went to Clairvaux and the author does not know where is it exactly. The answer is that Claivaux is the name of a prison located near the locality of Ville-sous-la-Ferté in the Aube department where Ephraim was arrested. This prison is still operating today.
2. Ephraim Kanarek's prisoner registration card from Auschwitz is available here :
https://collections.arolsen-archives.org/en/document/130830914
He signed it on the bottom left corner.
3. Ephraim's name appears on the Memorial of the Jews deported from France at
https://stevemorse.org/france/indexe.html