Pickering, Peter; Jefferson, Ingleby (2012). "Rainfall". Perim Island - The Last Colonial Outpost. Forum Gallery Aden. Archived from the original on July 6, 2015. Retrieved 2012-07-06.
Pickering, Peter; Jefferson, Ingleby (2012). "Rainfall". Perim Island - The Last Colonial Outpost. Forum Gallery Aden. Archived from the original on July 6, 2015. Retrieved 2012-07-06.