"PHMC Historical Markers Search". Pennsylvania Historical and Museum Commission. Commonwealth of Pennsylvania. Archived from the original(Searchable database) on March 21, 2016. Retrieved June 18, 2015.
Ashwill, Gary (September 12, 2009). "Ammon Field". Agate Type (blog). Retrieved November 24, 2016.
web.archive.org
"PHMC Historical Markers Search". Pennsylvania Historical and Museum Commission. Commonwealth of Pennsylvania. Archived from the original(Searchable database) on March 21, 2016. Retrieved June 18, 2015.