Another book on the list I would consider essential is Parallel and Concurrent Programming in Haskell: http://chimera.labs.oreilly.com/books/1230000000929
I also thoroughly enjoy the Functional Pearls series, many of which can be found on the Haskell wiki:
Re:A Haskell Reading List
by justsomething on Sunday May 01, 2016 @01:59PM
(#11607138)
"What I Wish I Knew When Learning Haskell", from the same author of the OP is also interesting from the "getting things done" perspective:
Most of those papers are really not "essential" for getting things done in Haskell.
If you want to dig deeper into Haskell's type system or Category Theory in general, then yes, there are a lot of good papers in that list.
If you just want to write safe, conscious and understandable code, then you are much better off reading the excellent "Haskell Programming from first priciples" [1] or the slightly outdated "Real World Haskell" [2].
[1] http://haskellbook.com/ [2] http://book.realworldhaskell.org/