1. Algeo, M. 2014. Pedestrianism: When Watching People Walk Was America’s Favorite Spectator Sport. Chicago, IL, USA: Chicago Review Press, Incorporated.
2. Bartolucci, F. and T. B. Murphy. 2015. “A Finite Mixture Latent Trajectory Model for Modeling Ultrarunners’ Behavior in a 24-Hour Race.” Journal of Quantitative Analysis in Sports 11:193.
3. Campbell, M. 1988. “A History of Multi Day Racing in the 1980s.” IAU Newsletter. September 1988, URL https://us.srichinmoyraces.org/archives/1988/ultra-trio/campbell-multiday, accessed 2019.01.14.
4. Deutsche Ultramarathon Vereinigung. Ultra Marathon Statistics, web page, URL http://statistik.d-u-v.org/geteventlist.php?year=all&dist=6d&country=all&Submit.x=24&Submit.y=2&label=&surface=all&sort=1&from=&to=, accessed 2019.01.14.
5. Dietrich, J. 2010. The Woodside Bunch: The Spirit of ’80 - 6 Day Race. web page, URL http://silverstrider.com/the-woodside-bunch/, accessed 2019.01.14.