Bernard Slager was married to Selma Boas. He was an accountant by profession and his wife was a maid servant. Their son Robert Leo was born in Westerbork transit camp on 6 July 1943.
Record of birth certificates of the Westerbork municipality, currently at the archives of Gemeente Midden-Drenthe in Beilen
In addition, Jokos files (numbers 998, 55528) on this family or other family members are at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk. The Jokos files reveal that a claim was lodged for compensation for valuables surrendered to the Lippmann-Rosenthal looting bank (L-claim, number 12).