[plt-scheme] Scribble doc referring to another Scribble doc

How do I put a hot-link in a Scribble document to another (standard, bundled) Scribble document?

There's an example in the doc that looks like
@secref[#:doc '(lib "scribblings/reference/reference.scrbl") "concurrency"]
or
@seclink[#:doc '(lib "scribblings/reference/reference.scrbl") "concurrency" "dummy link"]
which both work: they produce perfectly good HTML hotlinks.

But when I try to extend that analogy to a different library, like
@secref[#:doc '(lib "teachpack/2htdp/scribblings/2htdp.scrbl") "image"],
@secref[#:doc '(lib "teachpack/2htdp/scribblings/2htdp.scrbl") "universe"],
@seclink[#:doc '(lib "teachpack/2htdp/scribblings/2htdp.scrbl") "image" "the image teachpack"], or
@seclink[#:doc '(lib "teachpack/2htdp/scribblings/2htdp.scrbl") "universe" "the universe teachpack"],
the generated HTML code looks like
<font class="badlink">(part ("(lib teachpack/2htdp/scribblings/2htdp.scrbl)" "image"))</font>
or, at best,
<font class="badlink">the image teachpack</font>.

Stephen Bloch
sbloch at adelphi.edu