Osius, Alison (26 June 1993). "Obituary: Derek Hersey". The Independent. London. Retrieved 15 June 2013. (Gives Hersey's date of death incorrectly as 20 May 1993.)
Eldred, Sheila Mulrooney (8 April 2004). "Edge of Oblivion - Free-solo rock climbers feel spiritual lure". Fresno Bee., cited in "Yosemite Association - Newsroom". Yosemite Association. Archived from the original on 20 November 2008. Retrieved 27 February 2012.
yosemite.org
Eldred, Sheila Mulrooney (8 April 2004). "Edge of Oblivion - Free-solo rock climbers feel spiritual lure". Fresno Bee., cited in "Yosemite Association - Newsroom". Yosemite Association. Archived from the original on 20 November 2008. Retrieved 27 February 2012.