Mitchell, Glenford (5 October 1996). "Whatever happened to the Double Crusade?". Informal Talks by Notable Figures. Foundation Hall, US Baháʼí House of Worship, Wilmette, Illinois: Baháʼí Academics Resource Library. Retrieved 2010-01-23.
"Carta abierta a los pueblos de España". Official Website of the National Spiritual Assembly of the Baháʼís of Spain. National Spiritual Assembly of the Baháʼís of Spain. 1997. Archived from the original on 14 December 2009. Retrieved 2010-01-24.
"Most Baha'i Nations (2005)". QuickLists > Compare Nations > Religions >. The Association of Religion Data Archives. 2005. Archived from the original on 2010-04-14. Retrieved 2009-07-04.
"Carta abierta a los pueblos de España". Official Website of the National Spiritual Assembly of the Baháʼís of Spain. National Spiritual Assembly of the Baháʼís of Spain. 1997. Archived from the original on 14 December 2009. Retrieved 2010-01-24.
"Most Baha'i Nations (2005)". QuickLists > Compare Nations > Religions >. The Association of Religion Data Archives. 2005. Archived from the original on 2010-04-14. Retrieved 2009-07-04.