He is married to Antje de Vries.
They got married on May 4, 1918 at Achtkarspelen (Fr), he was 24 years old.Source 3
grandparents
parents
brothers/sisters
children
Tjitze Koster | ||||||||||||||||||
1918 | ||||||||||||||||||
Antje de Vries | ||||||||||||||||||
Geboorteregister 1893, Kollumerland c.a.
https://www.graftombe.nl/names/info/278350/koster
Huwelijksregister 1918, Achtkarspelen