"Adherents.com is a growing collection of over 43,870 adherent statistics and religious geography citations: references to published membership/adherent statistics and congregation statistics for over 4,200 religions, churches, denominations, religious bodies, faith groups, tribes, cultures, movements, ultimate concerns, etc. The religions of the world are enumerated here."
—Adherents.com home page, retrieved July 27, 2006.
"The Association of Religion Data Archives (ARDA) strives to democratize access to the best data on religion. Founded as the American Religion Data Archive in 1997 and going online in 1998, the initial archive was targeted at researchers interested in American religion. The targeted audience and the data collection have both greatly expanded since 1998, now including American and international collections and developing features for educators, journalists, religious congregations, and researchers. Data included in the ARDA are submitted by the foremost religion scholars and research centers in the world. Currently housed in the Social Science Research Institute at the Pennsylvania State University, the ARDA is funded by the Lilly Endowment, the John Templeton Foundation, and the Pennsylvania State University."
—About the ARDA, retrieved July 27, 2006.
The Hartford Institute for Religion Research (HIRR) "offers links to information that can help make the general public, and especially religious leaders, better consumers of poll and survey data."
—HIRR Statistics and Poll Data, retrieved July 27, 2006.