"Doomsday Clock 2019 Time". Bulletin of the Atomic Scientists. January 24, 2019. Archived from the original on January 24, 2019. Retrieved January 24, 2019.
Science and Security Board Bulletin of the Atomic Scientists (August 9, 2011). "It is two and a half minutes to midnight"(PDF). Bulletin of the Atomic Scientists. Archived from the original(PDF) on January 26, 2017. Retrieved January 26, 2017.
"Board moves the clock ahead". Bulletin of the Atomic Scientists (Press release). January 26, 2017. Archived from the original on January 26, 2017. Retrieved January 26, 2017.
"Current Time". Bulletin of the Atomic Scientists. Archived from the original on July 31, 2022. Retrieved December 7, 2020.
"2021 Doomsday Clock Statement"(PDF). Bulletin of the Atomic Scientists. January 27, 2021. Archived(PDF) from the original on January 27, 2021. Retrieved March 9, 2022.
"Doomsday Clock 2019 Time". Bulletin of the Atomic Scientists. January 24, 2019. Archived from the original on January 24, 2019. Retrieved January 24, 2019.
Science and Security Board Bulletin of the Atomic Scientists (August 9, 2011). "It is two and a half minutes to midnight"(PDF). Bulletin of the Atomic Scientists. Archived from the original(PDF) on January 26, 2017. Retrieved January 26, 2017.
"Board moves the clock ahead". Bulletin of the Atomic Scientists (Press release). January 26, 2017. Archived from the original on January 26, 2017. Retrieved January 26, 2017.
"Current Time". Bulletin of the Atomic Scientists. Archived from the original on July 31, 2022. Retrieved December 7, 2020.
"2021 Doomsday Clock Statement"(PDF). Bulletin of the Atomic Scientists. January 27, 2021. Archived(PDF) from the original on January 27, 2021. Retrieved March 9, 2022.