Links to Launch Equations

I’m going to create a small application to help track a balloon launch and subsequently predict the landing point shortly after burst.
Links to rocket equations:
http://my.execpc.com/~culp/rockets/rckt_eqn.html
Density of Air Calculations:
http://en.wikipedia.org/wiki/Density_of_air
Terminal Velocity and Drag:
http://microgravity.grc.nasa.gov/education/rocket/termvr.html
http://microgravity.grc.nasa.gov/education/rocket/flteqs.html