Hello folks. I was wondering if anyone could help me identify the AD&D Dungeon Master's Guide that I have.

I've checked out the very helpful flow chart and I think it's a fourth printing, but I'm not sure.

Some distinguishing characteristics:
TSR Wizard Logo and address on spine and lower right corner
"Advanced D&D," fits perfectly in the top left yellow banner.  
The forward by Mike Carr is dated 16 May 1979
The last page, 232, has the wizard logo next to, "TSR Games," above their WI address. All this is below an ad for Gen Con.
Endpapers are white and don't appear to be pasted over anything.
No offset print on page 99.
No Monster Manual pages.
No ISBN numbers anywhere that I can find.

So I think it's the 4th printing but I just wanted to be 100%

Here are some photos I took
Album — Postimages

Thank you very much for the help.
-Glenn

This looks like a 4th print to me.  I say this as one who has owned/still owns/etc. all variations of the DMG from the 1st thru 6th prints (including variations within a given printing) except for the mythological 3rd print.  I haven't seen any examples of any kind of 3rd print according to Acaeum guidelines.