This discovery places the Piauí alongside the ancient civilizations, as the various generic methods (few for 10,000 years of study!) have been important historical landmarks. The ours method seems to be the easiest, beautiful and very creative too.
Informal exposition (https://fr.slideshare.net/lossian/arithmetic-progressions-and-the-construction-of-doubly-even-magic-squares):
Formal exposition (https://fr.slideshare.net/lossian/arithmetic-progressions-and-the-construction-of-doubly-even-magic-squares-formal-exhibition-208857898):
Informal exposition (https://fr.slideshare.net/lossian/arithmetic-progressions-and-the-construction-of-doubly-even-magic-squares):
Formal exposition (https://fr.slideshare.net/lossian/arithmetic-progressions-and-the-construction-of-doubly-even-magic-squares-formal-exhibition-208857898):