"Postcodetool for 6411HP". Actueel Hoogtebestand Nederland (به هلندی). Het Waterschapshuis. Archived from the original on 21 September 2013. Retrieved 12 October 2013.
heerlen.nl
"Burgemeester Paul Depla" [Mayor Paul Depla] (به هلندی). Gemeente Heerlen. Archived from the original on 13 October 2013. Retrieved 12 October 2013.
web.archive.org
"Burgemeester Paul Depla" [Mayor Paul Depla] (به هلندی). Gemeente Heerlen. Archived from the original on 13 October 2013. Retrieved 12 October 2013.
"Postcodetool for 6411HP". Actueel Hoogtebestand Nederland (به هلندی). Het Waterschapshuis. Archived from the original on 21 September 2013. Retrieved 12 October 2013.