The archive file diffprob.zip contains the files:
|areash.pdf||Computing the surface area of a Sears-Haack body|
|areash.f90||Program for computing surface area|
|geopot.pdf||What is geopotential altitude (and why?)|
|hydro.pdf||Equations of hydrostatic equilibrium|
|oshock1.pdf||Wave angle for a given Mach and deflection angle|
|oshock.f90||Program for computing oblique shock|
None of these are what we call production programs. You can simply run them and modify them as needed to help you understand the problem.