This guide presents a comprehensive list of resources for the research and study of spatial audio, including: surround sound, binaural audio, ambisonics, and Dolby Atmos. You're gonna want to click through the menu on this one. Lowell has gathered a library of great information; all ye must do is seek.
Acknowledgments: Link descriptions are taken from the source websites. Special thanks to Dr. Michael G. Wagner, Head of the Digital Media Department at the Antoinette Westphal College of Media Arts & Design at Drexel University, for sharing his vast knowledge of spatial/immersive audio through his scholarship and YouTube channel.
This guide was created by Dr. Lowell Lybarger and is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License (CC BY-SA 4.0): https://creativecommons.org/licenses/by-sa/4.0/

Spherical Harmonics up to degree 3, as used in third-order Ambisonics.
https://commons.wikimedia.org/wiki/File:Spherical_Harmonics_deg3.png