https://www.fractuslearning.com/pln-twitter/
https://www.fractuslearning.com/education-twitter-profiles/
https://technologyembedded.wordpress.com/2012/05/20/twitter-101/
https://technologyembedded.wordpress.com/2012/07/19/deepen-your-digital-footprint-a-beginner-to-intermediate-guide-to-increasing-online-traffic-and-web-presence/