- Flask home page: http://flask.pocoo.org
- Flask documentation: http://flask.pocoo.org/docs/1.0/
- HTTP status codes: https://en.m.wikipedia.org/wiki/List_of_HTTP_status_codes
- stackoverflow Flask forum: https://stackoverflow.com/questions/tagged/flask
- W3School HTML: http://www.w3schools.com/html
- W3School CSS: https://www.w3schools.com/css/
- Bootstrap: https://getbootstrap.com
- ugradient: https://uigradients.com
- Heroku (PaaS): https://www.heroku.com