24 May 2016 Christophe Image published in: Article on econology in References, economic magazine Image available in: 400 x 606 / 150 x 150 / 198 x 300 / 400 x 606 / 400 x 606 / 400 x 400 / 400 x 606 / 33 x 50 / 99 x 150 / 165 x 250