Ready References
A Guide to Backyard Astronomy
Understanding Celestial Coordinates
Choosing Your First Telescope
Hands-On Astrophysics (HOA)
Introduction to Partial Differential Equations
Introduction to Object-Oriented Software
Notes on the Construction and Design of Instruments and Apparatus
Ready References Understanding Celestial Coordinates 
Introduction to Partial Differential Equations Introduction to Object-Oriented Software 
Notes on the Construction and Design of Instruments and Apparatus