Recommends 'wdg-html-reference' package, but it doesn't exists

Binary package hint: quanta

quanta recommends wdg-html-reference:

servidor@servidor:~$ apt-cache show quanta | grep Recommends
Recommends: cervisia, gnupg, kompare, kxsldbg (= 4:3.5.5-0ubuntu1), phpdoc, wdg-html-reference, docbook-defguide

However, wdg-html-reference is missing:

servidor@servidor:~$ sudo apt-get install wdg-html-reference
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package wdg-html-reference is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package wdg-html-reference has no installation candidate