JSON:https://beginnersbook.com/2015/04/json-tutorial/
RESTful API: https://mlsdev.com/blog/81-a-beginner-s-tutorial-for-understanding-restful-api
HTML5: https://www.w3schools.com/html/html5_intro.asp
https://www.codecademy.com/learn/learn-html
css3: https://www.w3schools.com/css/
https://www.codecademy.com/learn/learn-css
Bootstrap: https://www.w3schools.com/bootstrap/
https://www.codecademy.com/learn/make-a-website
Java: https://www.tutorialspoint.com/java/index.htm
https://www.codecademy.com/learn/learn-java
Angular2: https://app.pluralsight.com/library/courses/angular-2-getting-started-update/table-of-contents