“Abraham and Isaac”. Kent State University Libraries and Media Services, Department of Special Collections and Archives. April 17, 2007閲覧。
“May 4 Memorial (Kent State University)”. Kent State University Libraries and Media Services, Department of Special Collections and Archives. April 16, 2007閲覧。
“Biography of May 4 speakers”. KentWired (May 2, 2010). 28 September 2017閲覧。 “Casale told DrownedInSound.com, an online music magazine, that May 4, 1970, was the day he stopped being a hippie. 'It was just so hideous,' he said. 'It changed everything: no more mister nice guy.'”
Kent State: A Requiem 'The play was first performed as a Readers Theatre production as Kent State: A Wake at Yale University and Occidental College in 1976'. May 4 Archive.org. Retrieved January 20, 2014.
Shots Still Reverberate For Survivors Of Kent State 'Dean Kahler, who was paralyzed during the shootings, went on to become a high school teacher and covered the events of May 4 in his classes' NPR News, May 3, 2010. Retrieved January 20, 2014.
"Tom Laughlin dies at 82" "The 1974 'The Trial of Billy Jack' was also a hit, in which Laughlin attacked such events as Kent State". Variety.com, 15 December 2013. Retrieved January 21, 2014.
Dean Kahler: Visitors' Center helps him move past May 4, 1970 'Dean Kahler, among the most severely wounded of the 13 Kent State students shot by the National Guard on May 4, 1970, tours the new May 4th Visitors' Center being dedicated this weekend' WKSU, May 3, 2013. Retrieved January 20, 2014.