Chock-full of AD&D content, not all of it particularly relevant, but almost all of it interesting, issue 66 shows the increasing domination of AD&D in terms of magazine content as it grows much faster than other games TSR is producing. 

There’s an article debating if spellcasters should or should not be allowed edged weapons, another translating character from the Elfquest comic book into AD&D characters, new AD&D characters including the Marid and the Dao (which has already appeared in the Tsojcanth module), a Gygax penned addition of a bunch of spells for Illusionists (including such classics as Chromatic Orb, Alter Self or Dispel Magic). Keeping on the subject of Illusions Tom Armstrong writes about real and fake effects of illusions. 

Then we get a whole special section on languages, which not being tied to any specific setting is a bit pointless. It includes a dictionary of Thieves’ Cant that you can cut out and fold in order to have a litte portable dictionary. There are also more general articles on including languages in your campaign and creating a variety of dialects within a party, another article covers Dwarvish as a language. Closing out the AD&D articles, Leomund’s Tiny Hut brings us a bunch of tiny creatures to challenge lower level characters.