Attributions:
Fig. 1 Modification of Original Work – "Der Sattler" – Woodcut by Jost Amman (1539 - 1591),
as published in The Book of Trades by Sigmund Feierabend, Frankfurt am Main, Germany,
in 1568, ['Der Sattler' by Jost Amman is in the Public Domain
Permission: Author died more than 70 years ago - public domain
[{{PD-1996}} – public domain in a source country on January 1, 1996 and in the US].
Fig. 2 Source: pexels.com - Creative Commons Zero (CC0) license. Attribution is not required.
Fig. 3 Former stock exchange of Frankfurt, Germany during Luminale 2014.
Attribution: Norbert Nagel [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], from Wikimedia Commons
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The author of this file, Norbert Nagel, published this file under the license CC-BY-SA-3.0 on Wiki media Commons.
_JPG.jpg)
Fig. 4 Title: "Nero and Seneca" - Artist: Eduardo Barrón González -Spanish sculptor (1858-1911)
Attribution: [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], from
Wikimedia Commons