Mozes van der Sluis and Grietje Roos were married at Westerbork transit camp on 26 February 1943. At the marriage ceremony Mozes van der Sluis declared to acknowledge paternity of Alfred Roos, son of Grietje Roos.
Record of marriage certificates of the Westerbork municipality, currently at the archives of Gemeente Midden-Drenthe in Beilen