About Dressage, International Equestrian Federation, retrieved August 26, 2011
FEI Dressage Rules 24th edition(PDF). Lausanne, Switzerland: International Equestrian Federation. 2013. p. 36. Archived from the original(PDF) on June 26, 2013. Retrieved August 12, 2016.
FEI Dressage Rules 24th edition(PDF). Lausanne, Switzerland: International Equestrian Federation. 2013. p. 36. Archived from the original(PDF) on June 26, 2013. Retrieved August 12, 2016.