Segundo o website, ele libera o conteúdo sob cc-by-sa-3.0, como forma de divulgação do trabalho.
Licensing
Original image: Leonardo da Vinci, the image is in public domain due to age.
The rest:
Public domainPublic domainfalsefalse
This image of simple geometry is ineligible for copyright and therefore in the public domain, because it consists entirely of information that is common property and contains no original authorship.
Captions
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