- https://github.com/naver/billboard.js
- https://github.com/wbkd/awesome-d3
- D3 changes from V3 to v4 https://github.com/d3/d3/blob/master/CHANGES.md
A good example of a working D3 chart in v4 https://jsfiddle.net/jnxh140f/
how selections work - https://bost.ocks.org/mike/selection/