On 8 August 1941 the Joodsche Weekblad published an obituary submitted by Joseph Gobes for his son, who was 23 when he died. The notice did not mention that Gerrit Gobes had been killed in Mauthausen.
Het Joodsche Weekblad, 8 August 1941, 11

Gerrit Gobes- ongehuwd - geboren op 10-04-1918 en vermoord op 28-07-1941 in Mauthausen. Hij werd tijdens de eerste razzia in Amsterdam opgepikt. (Februari groep ? )

In addition, a Jokos file (number 10475) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.