[Haskell-cafe] Location of library documentation with 6.12.1?

Hi, I've just upgraded from 6.10.1 to 6.12.1 and can't seem to find all the library documentation. This page is apparently the documentation root: http://www.haskell.org/ghc/docs/6.12.1/html/ but if I click through to the Haskell Hierarchical Libraries page http://www.haskell.org/ghc/docs/6.12.1/html/libraries/index.html I can't for example find Control.Monad.State. I guess I'm missing something obvious about how things are organised? thanks in advance, Roly