iteration: link to the original Transducers document

iteration.md

@@ -207,8 +207,10 @@ The user is free to invent their own transducers (i.e. functions like `map`) and
 reducers (i.e. functions like `+`) to traverse data streams in any way they
 wish, all while being very memory efficient.
 
-See [its README](https://git.sr.ht/~fosskers/cl-transducers) or [its
-API](https://fosskers.github.io/cl-transducers/index.html) for more information.
+See [its README](https://git.sr.ht/~fosskers/cl-transducers), [its
+API](https://fosskers.github.io/cl-transducers/index.html), or the [original
+Transducers document](https://clojure.org/reference/transducers) for more
+information.
 
 ## Recipes