The one basically arguing for why it’s a natural-language programming language. It’s not on the inform 7 website anymore, and I’ve been looking but can’t find a copy elsewhere.
Is it the third link in these search results – the PDF from tufts.edu?:
Talking of Graham Nelson papers, is there a place to also download IF theory papers by Graham?
That’s the one!
Do a search for IF Theory Reader edited by Kevin Jackson-Mead and J Robinson Wheeler. This includes a number of interesting papers, including three by Graham.
His classic is The Craft of Adventure, 2nd edn, dated January 1995, but I think this is superseded by Chapter VIII of The Inform Designer’s Manual, 4th edn, dated 2001. You can find this in various formats at the IF Archive.