Operation Hardtack I Fact Sheet(PDF), Fort Belvoir, VA: Defense Threat Reduction Agency, May 1, 2015, archived from the original(PDF) on February 29, 2020, retrieved April 19, 2016
Operation Hardtack I(PDF) (DNA6038F, ADA136819), United States of America Department of Defense, 1958, archived(PDF) from the original on October 19, 2016, retrieved April 19, 2016
Hoerlin, Herman (October 1976), United States High-Altitude Test Experiences: A Review Emphasizing the Impact on the Environment (LA-6405), LA (Series) (Los Alamos, N.M.)6405, Los Alamos Scientific Laboratory, hdl:2027/mdp.39015086460626 Reference for time zone at Johnston Island 1958-1962.
Sublette, Carey (6 August 2021). "Gallery of U.S. Nuclear Tests". Nuclear Weapon Archive. Archived from the original on 5 February 2021. Retrieved 8 February 2021.
Operation Hardtack I Fact Sheet(PDF), Fort Belvoir, VA: Defense Threat Reduction Agency, May 1, 2015, archived from the original(PDF) on February 29, 2020, retrieved April 19, 2016
Operation Hardtack I(PDF) (DNA6038F, ADA136819), United States of America Department of Defense, 1958, archived(PDF) from the original on October 19, 2016, retrieved April 19, 2016
Sublette, Carey (6 August 2021). "Gallery of U.S. Nuclear Tests". Nuclear Weapon Archive. Archived from the original on 5 February 2021. Retrieved 8 February 2021.