- FamilySearch Family
- FamilySearch Family Tree (http://www.familysearch.org) - "FamilySearch," database, \i FamilySearch\i0 - The Church of Jesus Christ of Latter-day Saints - accessed 24 Jun 2016), entry for Claas Hoorn, person ID K8N1-NYP.
- FamilySearch Family Tree (http://www.familysearch.org) - "FamilySearch," database, \i FamilySearch\i0 - The Church of Jesus Christ of Latter-day Saints - accessed 24 Jun 2016), entry for Claas Hoorn, person ID KCKP-NG7.
» Les sources » Arbre généalogique M. Tolsma » Généalogie Online">
- FamilySearch Family
- FamilySearch Family Tree (http://www.familysearch.org) - "FamilySearch," database, \i FamilySearch\i0 - The Church of Jesus Christ of Latter-day Saints - accessed 24 Jun 2016), entry for Claas Hoorn, person ID K8N1-NYP.
- FamilySearch Family Tree (http://www.familysearch.org) - "FamilySearch," database, \i FamilySearch\i0 - The Church of Jesus Christ of Latter-day Saints - accessed 24 Jun 2016), entry for Claas Hoorn, person ID KCKP-NG7.
» Les sources » Arbre généalogique M. Tolsma » Généalogie Online">