See Mac OS.
"System 1." YourDictionary, n.d. Web. 19 October 2018. <http://www.yourdictionary.com/system-1>.
System 1. (n.d.). Retrieved October 19th, 2018, from http://www.yourdictionary.com/system-1
Yes, I'd like to receive Word of the Day emails from YourDictionary.com
By continuing, you agree to our
Please set a username for yourself.
People will see it as Author Name with your public flash cards.