“File:A Shipping Manager Checking Delivery Inventory Cartoon.svg” by Free Clip Art is licensed under CC BY-SA 4.0
Mohamed Mahmoud Hassan has released “Man Thinking” image under License: CC0 Public Domain
Dawn Hudson has released “Columbo Clipart” image under License: CC0 Public Domain
Petr Kratochvil has released “Filling Up The Test Tubes” image under CC0 1.0 Public Domain
Frits Ahlefeldt has released “Money Fight” image under License: CC0 Public Domain
Leonardo da Vinci collage includes photos licensed by depositphotos.com and public domain photos from picryl.com
Intellectual Property by Nick Youngson CC BY-SA 3.0 Alpha Stock Images
“File:Library building clipart.svg” by https://openclipart.org/user-detail/oksmith CC0 1.0
Sultan Ibrahim Building, Johor Bahru by derkommander0916 https://openclipart.org/detail/223586/sultan-ibrahim-building-johor-bahru CC0 1.0
Football Arena by lekamie https://openclipart.org/image/800px/181702 CC0 1.0
Hand and Money by j4p4n https://openclipart.org/image/800px/283266 CC0 1.0
Mathematics formulas https://commons.wikimedia.org/wiki/File:Pure-mathematics-formul%C3%A6-blackboard.jpg this work has been released into the public domain by its author, Wallpoper.
Presentor illustration Depositphotos_47688411_l-2015.jpg purchased license
Gerd Altmann has released “Binary Thinking” image under Public Domain license CC0 Public Domain.
File:”The School of Athens” By Raphael – Stitched together from vatican.va, Public Domain, https://commons.wikimedia.org/w/index.php?curid=4406048
Witelo-de-natura from https://picryl.com/media/title-page-of-witelo-de-natura-illus-with-composite-of-various-phenomena-of public domain
www.publicdomainpictures.net/en/view-image.php?image=271602&picture=team-building
www.publicdomainpictures.net/en/view-image.php?image=147052&picture=background-wallpaper
www.publicdomainpictures.net/en/view-image.php?image=373987&picture=global-digitization-201105