https://study.com/academy/lesson/what-are-social-networks-types-examples-quiz.html
https://www.martechadvisor.com/articles/social-media-marketing-2/viral-coefficient-and-tips-for-viral-marketing/
https://www.flickr.com/photos/eu_echo/11599327704
https://www.flickr.com/photos/ninian_reid/49317142152
https://commons.wikimedia.org/wiki/File:Black_Lives_Matter_in_Stockholm_2020.jpg
https://www.flickr.com/photos/48954087@N07/4484636562
https://steemit.com/steem/@steemrollin/viral-marketing-viral-loops-and-the-viral-coefficient