M. A. Zingg, C. A. Rust, T. Rosemann, R. Lepers, and B. Knechtle, “Runners in their forties dominate ultra-marathons from 50 to 3,100 miles”, Clinics, vol. 69, no. 3, pp. 203–211, Mar. 2014, doi: 10.1590/clin.v69i3.77113.