Reading Terry Pratchett as a Tolkienist

Now, this is something I have been wanting to do for a long time: Reading all of Terry Pratchett's Discworld novels - again - but this time I am looking explicitly for Tolkien references. With the eyes of an eagle and the ears of a fox! You know what I am talking about! 

I am also quite happy to dive in way deeper than I have ever done before on Pratchett. One of the sources I will be using is the Annotated Pratchett File, v9.0 (Abre numa nova janela).