Research: Project4Dimensions
jsOnclickDisabled shows a JavaScript instruction to disable a button after being clicked.
See index.html in docs.
http://project4dimensions.github.io/jsOnclickDisabled/
Marks, Steve. 2010. “Disabling the Submit Button to Prevent Double Form Submission.”
BIOSTALL. December 21.
http://biostall.com/disabling-submit-button-to-prevent-double-form-submission/.
Zarel. 2009. “Onclick=‘This.Disabled=True;Return True;’ - Technology.” Zybez RuneScape Community Forums. December 15. http://forums.zybez.net/topic/1329090-onclickthisdisabledtruereturn-true/.