Whatever you can get for them. Don't believe they are scarce, but I don't know if they are currently in print. You might check Amazon or other such sources. These are excellent reference books that complement any gun library.

Just be careful of the data. Some of it, maybe much of it, doesn't appear to be safe and very few loads were pressure tested. Ackley didn't shoot the data, just published what others who worked with or developed
the various cartridges sent him. Few had chronographs then as well, so a lot of the muzzle velocities may be a bit optimistic.