NASA
Nasa: Predictions for the 2004 Transit of Venus
NASA site provides detailed information on the 2004 transit of Venus across the sun. Also explores the modern value of Venus transits and how they aid in the study of astronomy.
Smithsonian Institution
Smithsonian Libraries:chasing Venus: Observing the Transits of Venus 1631 2004
An online website, from a historical perspective, of the study of the transit of Venus between the sun and the earth.
NASA
Nasa: History of Venus Transit
NASA site recounts the history of the Venus Transits that have occurred over the past centuries and the various descriptions astronomers have written about them.