"New Forest Pony Stallions". Nfstallions.info. October 2, 2011. Retrieved November 6, 2011.(This site has photographs and video of group-kept stallions)
ovs0.com
Schumacher, James. "Penis and prepuce." Equine surgery 2 (2006): 540–557.
Smith Thomas, Heater (July 1, 2004). "Stallion or Gelding?". The Horse. Retrieved March 3, 2014.
verderers.org.uk
"MINUTES of the Court of Verderers"(PDF). October 19, 2005. p. 3. Retrieved December 26, 2011.(Document refers to the local group-keeping of stallions: 15 stallions on winter grazing at New Park, 20 stallions at Cadland, and to free winter grazing to all stallions passed to run on the Forest, "all those stallions will now remain at our two secure grazing sites at New Park and the Manor of Cadland")
"MINUTES of the Court of Verderers"(PDF). April 15, 2009. p. 3. Retrieved December 24, 2011.(Document refers to the group-keeping of 22 stallions at Cadland)