Sources:
George Hart for The Simons Foundation, Bicycle Tracks - Which Way Did the Bicycle Go? https://www.youtube.com/watch?v=ETnbfZUW8zY
David Finn, Can a bicycle create a unicycle track. https://www.maa.org/sites/default/files/pdf/upload_library/22/Polya/Finn.pdf
Stan Wagon, Notes on the Unicycle Puzzle.
http://stanwagon.com/public/1248UnicycleSolution.pdf
Mark Levi and Serge Tabachnikov, On bicycle tire tracks geometry, hatchet planimeter, Menzin’s conjecture, and oscillation of unicycle tracks
http://www.personal.psu.edu/sot2/prints/bicycle9.pdf
Please let me know about the mistakes I've probably made!