• How to Secure SSH with Google Authenticator Two-Factor Authentication http://www.howtogeek.com/121650/how-to-secure-ssh-with-google-authenticators-two-factor-authentication/ 22 comments 16/8/2012 linux
• How to Secure SSH with Google Authenticator’s Two-Factor Authentication - How-To Geek http://www.howtogeek.com/121650/how-to-secure-ssh-with-google-authenticators-two-factor-authentication/ 69 comments 22/1/2013 netsec
• Two-factor SSH authentication via Google secures Linux logins | TechRepublic http://www.techrepublic.com/blog/opensource/two-factor-ssh-authentication-via-google-secures-linux-logins/2607?tag=nl.e011 25 comments 21/6/2011 sysadmin
• Two-factor SSH authentication via Google secures Linux logins. Two-step verification - Google Project Hosting http://code.google.com/p/google-authenticator/ 10 comments 24/6/2011 linux