He is married to Antje van der Hoek.
They got married on May 20, 1916 at Oostdongeradeel, Friesland, Nederland, he was 23 years old.Source 3
grandparents
parents
brothers/sisters
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Klaas de Graaf | ||||||||||||||||||
1916 | ||||||||||||||||||
Antje van der Hoek | ||||||||||||||||||
Geboorteregister 1893, Oostdongeradeel
https://www.graftombe.nl/names/info/108103/graaf_de
Huwelijksregister 1916, Oostdongeradeel