References:
Prasanna Venkatesh on LinkedIn
What is a Group? Youtube
What is Group theory? Wikipedia
Rubik's Cube group Wikipedia
Notes for a 2-week course on Rubik's Cube and Group Theory taught by Janet Chen - a senior preceptor at Harvard University
A course on Modern Algebra
Intro and Outro music by Lee Rosevere 'Here's the thing' from Music for Podcasts 3
Corrigendum: A 180 degree rotation for a rectangle is also a symmetry. A zero degree rotation is the identity element for the rectangle symmetry group.