The following publications contain information about John Sivertsen:
Article: "Pvt. Sivertsen's Horse: Victim of Little Big Horn" by Sandy Barnard •Artifacts recovered with the remains of a horse found along one of the retreat routes used by the Reno battalion suggest the animal was the mount of Pvt. John Sivertsen, Company M. • Greasy Grass, Annual of the Custer Battlefield Historical & Museum Association • Vol. 12 • May 1996.
Article: "John Sivertsen's Story of the Battle: A 7th Cavalry survivor's account of the Battle of the Little Bighorn" by Bruce Brown • Astonisher.com • Undated • Accessed August 15, 2025.