- https://marketingplatform.google.com/about/analytics/

- https://medium.com/web-development-zone/top-free-website-statistic-tools-464599c98154

- https://www.hongkiat.com/blog/top-14-free-web-statistics-tools/

- https://clickhelp.com/online-software-documentation-tool/?utm_source=medium-com&utm_medium=brad-top-link&utm_campaign=blogging