Ready References
Essential Technologies for Making Accurate PC-Based Measurements
Hands-On Astrophysics (HOA)
First Aid for Electrical Accidents
The Severity of an Earthquake
AAVSO Membership Information
Further Reading on Fossils
Ready References Essential Technologies for Making Accurate PC-Based Measurements Hands-On Astrophysics (HOA) 
First Aid for Electrical Accidents The Severity of an Earthquake AAVSO Membership Information Further Reading on Fossils