Morning Blue — Josh Woodward · CC BY 4.0 · excerpts and modified versions
https://www.joshwoodward.com/sharing/

Big Buck Bunny © 2008 Blender Foundation / www.bigbuckbunny.org · CC BY 3.0 · excerpts and modified versions
https://peach.blender.org/about/

老残游记 · 刘鹗 · reader HC / LibriVox · public domain recording
https://librivox.org/lao-can-you-ji-by-liu-o/

Field Notes illustrations, demonstration captions and geometric animation: original Audiosubvideo sample assets.
https://audiosubvideo.com/about
License: https://creativecommons.org/licenses/by/4.0/
License: https://creativecommons.org/licenses/by/3.0/
LibriVox: https://librivox.org/pages/public-domain/