Sources/Full performances:
#5 E. Rzhavinskii (or A. Danilkin ?), 1963, https://youtu.be/gEp2RrsjqlI
#4 Emöke Ritter, 1993, https://youtu.be/JeIPolhqVSM ,
https://youtu.be/QZhvTekOays
#3 Judy Kelly, 1950, https://youtu.be/lIdAduAAmig
#4 Alexander Romanovskii, 1983, https://youtu.be/NqQ_F1iiIIY
#5 Bobylev, 2013, https://youtu.be/NjUOBZvyogA
Thumbnail picture: https://emuseum.ringling.org/emuseum/objects/9409/forepaughsells-shows-combined-phenomenal-acts-of-contortio (The Ringling's online collections)
