1. https://www.youtube.com/playlist?list=PL-osiE80TeTs4UjLw5MM6OjgkjFeUxCYH
2. https://www.udemy.com/python-flask-tutorial-step-by-step/
3. http://flask.pocoo.org/docs/1.0/tutorial/
4. https://www.tutorialspoint.com/flask/flask_quick_guide.htm
5. https://www.youtube.com/playlist?list=PL6gx4Cwl9DGDi9F_slcQK7knjtO8TUvUs
6. https://www.youtube.com/playlist?list=PLillGF-RfqbbbPz6GSEM9hLQObuQjNoj_