https://app.codesignal.com/ https://www.hackerrank.com/ https://leetcode.com/ https://coderbyte.com/ http://www.programcreek.com/2012/11/top-10-algorithms-for-coding-interview/ http://www.careercup.com/ https://www.w3resource.com/java-exercises/ http://www.w3schools.com/quiztest/quiztest.asp?qtest=HTML https://hackernoon.com/50-data-structure-and-algorithms-interview-questions-for-programmers-b4b1ac61f5b0
- http://www.amazon.com/Head-First-Design-Patterns-Freeman/dp/0596007124/
- http://www.amazon.com/Effective-Java-Edition-Joshua-Bloch/dp/0321356683/
- http://www.amazon.com/Clean-Code-Handbook-Software-Craftsmanship/dp/0132350882/
- http://www.amazon.com/Cracking-Coding-Interview-Programming-Questions/dp/098478280X/
Effective Java: https://github.com/HugoMatilla/Effective-JAVA-Summary