Ready References
A Guide to Backyard Astronomy
Using a Naked-Eye Starmap
Beating the Seeing
AAVSO Historical Light Curves
Making Variable Star Observations
Notes on the Materials of Research
Major Divisions of Geologic Time
Ready References A Guide to Backyard Astronomy 
Using a Naked-Eye Starmap Beating the Seeing 
AAVSO Historical Light Curves 
Making Variable Star Observations 
Notes on the Materials of Research Major Divisions of Geologic Time