They had no children.

Notes:

• Employment: kantoorbediende
• Religion: Roman Catholic
• Witnesses at Johannes Jacobus's birth: Maria Visser, 46 years old, midwife, living in Rotterdam & Martinus Brinkman, 34 years old, clerk, living in Rotterdam & Wilhelmus Johannes Pluch, 23 years old, clerk, living in Rotterdam
• Witnesses at Gerda's birth: Antonia Castelijns, wife of Franciscus Gerardus Schumaker, 38 years old, midwife, living in Rotterdam & Anthonie Dirk van Luijn, 39 years old, mail carrier, living in Rotterdam & Leendert Arnold, 36 years old, mail carrier, living in Rotterdam
• Witness at Johannes's death: Alphonsus Nihof, 41 years old, bedienaar, living in 's-Gravenhage

Sources:

1. "Netherlands, Zuid-Holland Province, Civil Registration, 1679-1942." Database with images. FamilySearch. http://FamilySearch.org : 14 June 2016. Nationaal Archief, Den Haag (National Archives, The Hague).
2. Digitale Stamboom Den Haag. http://denhaag.digitalestamboom.nl/