Gijsbert Tromp en tant qu·Äôentrâ©e de Johanna Tromp, "Netherlands, Archival Indexes, Vital Records, 1600-2000"
"Nederland, Indexen van de Archieven, Primaire Archiefstukken (BS en DTB), 1600-2000," database,
FamilySearch (
https://familysearch.org/ark:/61903/1:1:QL4W-78TD : 23 August 2017), Gijsbert Tromp in entry for Johanna Tromp, Birth 25 Dec 1820, Heukelum, Gelderland, Nederland; from database,
openarchives (https://www.openarch.nl : 2016); citing Heukelum, archive 0207, inventory number 33817, record number 15; ; Gelders Archief.