Pictures ( last access to all sources October 22nd, 2017):

• http://schueleronline.wixsite.com/schueler-redaktion/impressum
• https://lever-client-logos.s3.amazonaws.com/70522f2d-e3d5-4ffc-b1d9-f1c393be0275-1497632617967.png
• http://alicantehoy.es/wp-content/uploads/2016/12/NewtonAir1.jpg
• https://lh3.googleusercontent.com/WxZMFfNB3tghDto75Isfs0d1-QO8Dlf6E7wNMrZbr8naX2Rr9HnCjmfUVEKwophJBGGM=s150

Infographic:

Thank you, @daniela_FOL for your amazing infographic.