From the U.S. Department of the Interior, National Park Service, National Center for Preservation Technology and Training (
http://www.ncptt.nps.gov )
Cemetery Restoration Resources
http://www.ncptt.nps.gov/index.php/cemetery-restoration-resources/Related article.
11 APR 2007 "Stopping the hands of time. 9 steps for cemetery preservation" by Mary Striegel
http://www.ncptt.nps.gov/index.php/stopping-the-hands-of-time-9-tips-for-cemetery-preservation/