mach buffet speeds

[flybubba]

I understand the difference between high and low speed buffet (often confused with stall). Most jets have cruise charts which will show the two buffet speeds and the "coffin corner" at higher altitudes. I am trying to find how these speeds are calculated from an explicit equation and also how this equation relates to alpha. I understand this can be derived from adiabatic compressible flow, but if anyone can point out a good reference, it would be appreciated.