Fonte positiva dos dados

Sec. de: Leonardo da Vinci... 2014

http://authorities.loc.gov 7/5/2015

http://viaf.org/processed/BNF%7C13341687: (historiador; d.n.)

http://viaf.org/processed/DNB%7C136520758: (d.n.)

http://viaf.org/processed/NTA%7C171555759: (d.n.)