Archivo: Leonardo da Vinci helicopter

Description: Leonardo da Vinci: Entwurf eines Helikopters
Title: Leonardo da Vinci helicopter
Credit: ausschnitt aus http://commons.wikimedia.org/wiki/Image:Leonardo_da_Vinci_helicopter_and_lifting_wing.jpg
Author: Leonardo da Vinci
Permission: This work is in the public domain in its country of origin and other countries and areas where the copyright term is the author's life plus 100 years or less. You must also include a United States public domain tag to indicate why this work is in the public domain in the United States. This file has been identified as being free of known restrictions under copyright law, including all related and neighboring rights.
Usage Terms: Public domain
License: Public domain
Attribution Required?: No