www.ultraned.org

Anchor text: John Foden's article on how the Spartathlon has changed over the years

Wikipedia: Spartathlon

Anchor text: John Foden's article on time spent at refreshment points

Wikipedia: Spartathlon

Anchor text: De eerste Olympische marathon

Wikipedia: Aristidis Konstantinidis

Anchor text: Jan Knippenberg Memorial

Wikipedia: Jan Knippenberg

Anchor text: Dead Sea Ultramarathon 2001

Wikipedia: Lambert Schuurs