books on Parkers -- ratings?

[OH Osthaus]

after our recent enlightened discussion on e books

I thought this might be both interesting to both new and old forum members

There have been several books done on the Parker Shotgun, from Johnson's little tome to the two volume Parker Story set, as well as Muderlak's works and more. I have several, and of course I still need some others, and there will be many new members wont have any yet.

So how would the readers here rank the various titles? Parker titles only, there are shelves full ( mine at least) of generic double shotgun interest books.

based on value of the information available in them what would your ranking be -- could be as a must have vs nice to have or best reading or too much outdated research information.