1
Blazing a Ghostly Trail [E-Book] : ISON and Great Comets of the Past and Future /
2
Mars and How to Observe It [E-Book] /
Other Personal Name(s): ...Grego, Peter...

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3
Galileo and 400 Years of Telescopic Astronomy [E-Book] /
Other Personal Name(s): ...Grego, Peter....

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4
Astronomical Cybersketching [E-Book] : Observational Drawing with PDAs and Tablet PCs /
5
Venus and Mercury, and how to observe them / [E-Book]
Other Personal Name(s): ...Grego, Peter....

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