Image: Hermann Minkowski signature

Description: Signature of Hermann Minkowski
Title: Hermann Minkowski signature
Credit: This is a retouched picture, which means that it has been digitally altered from its original version. Modifications: traced. The original can be viewed here: De Raum zeit Minkowski Bild Signature (cropped).jpg: .  
Author: Hermann Minkowski
Permission: This signature is believed to be ineligible for copyright and therefore in the public domain because it falls below the required level of originality for copyright protection both in the United States and in the source country (if different). In this case, the source country (e.g. the country of nationality of the signatory) is believed to be Germany. Note that this tag cannot be used on all signatures, as not all signatures are copyright-free. See Commons:When to use the PD-signature tag for an explanation of when the tag may be used.
Usage Terms: Public domain
License: Public domain
Attribution Required?: No