Ready References
A Guide to Backyard Astronomy
Understanding Celestial Coordinates
Using a Map at the Telescope
Using the Hands-On Astrophysics Manual
Essential Technologies for Making Accurate PC-Based Measurements
The Interior of the Earth
A Glossary of Seismic Terms
Ready References Understanding Celestial Coordinates Using the Hands-On Astrophysics Manual Essential Technologies for Making Accurate PC-Based Measurements 