Links & References

For this exercise we used existing materials from various sources, that we also recommend to you for learning D3:

• A book: D3.js in Action (2015) -- Elijah Meeks, Manning Publication co. (New York). ISBN: 9781617292118 (in ITC library);
• The D3 website at http://d3js.org/, with the official API documentation and many D3 Examples and tutorials;
• The first section of this exercise was based on the 3 Little Circles tutorial at http://bost.ocks.org/mike/circles/.
• A useful reference for the JavaScript Language in general can be found at W3Schools Javascript Reference. This site also has equally good references for SVG, CSS and HTML...