[1] Vincent van Gogh and Learning, http://www.learningsolutionsmag.com/articles/1560/emea-reporter-vincent-van-goghpainterand-learning-coach, accessed on January 20, 2016 at 12:07 pm CET.
[2] How to Think Like Leonardo da Vinci by Michael Gelb, http://michaelgelb.com/programs/how-to-think-like-leonardo-da-vinci/, accessed on January 20, 2016 at 12:08pm CET.