| Willem Alfred Koumans |
| Willem Alfred Koumans | |
| G: | 16 aug 1927 |
| Delft | |
| O: | 20 apr 2001 |
| Den Haag | |
|
| Robert Herman Cato Koumans |
| Robert Herman Cato Koumans | |
| G: | 11 mei 1892 |
| Oengaran (Semarang, Ned. Ind.) | |
| O: | 14 mrt 1942 |
| Sachsenhausen (D) | |
| Johanna Ida Stortenbeker |
| Johanna Ida Stortenbeker | |
| G: | 6 mei 1895 |
| Buitenzorg (Ned. Ind.) | |
| H: | 18 aug 1924 |
| Rijswijk | |
| O: | 28 jan 1983 |
| Leidschendam | |