The Eratosthenes Project
- Gives information about the techniques and computations used by this ancient mathematician to find the circumference of the earth. Includes sample sketch and reconstructed map of the world.
- http://www.phys-astro.sonoma.edu/observatory/eratosthenes/

Wikipedia - Eratosthenes
- Brief article covers his life and work. Includes links for further reading.
- http://en.wikipedia.org/wiki/Eratosthenes

Eratosthenes of Cyrene
- Biography of the mathematician, geographer and astronomer born 276 BC in Cyrene, North Africa (now Shahhat, Libya). From The MacTutor History of Mathematics archive.
- http://www-history.mcs.st-andrews.ac.uk/Biographies/Eratosthenes.html

Eratho
- Brief information on Eratosthenes, including when and where he was born, as well as later historians that followed up on his work of the stars.
- http://www.pbs.org/wnet/hawking/cosmostar/html/cstars_eratho.html