Mahout parallel K-Means - algorithms analysis‏

To whom it may correspond,

Hello, I have been checking the algorithm of Mahout 0.9 version k-means
using MapReduce and I would like to know where can I check the code of
what is happening inside the map function and in the reducer?

I was debugging using NetBeans and I was not able to find what is exactly implemented in the Map and Reduce functions...

The reason what I am doing this is because I would like to know what
is exactly implemented in the version of Mahout 0.9 in order to see
which parts where optimized on the K-Means mapReduce algorithm.

Do you know which research paper the Mahout K-means was based on or where can I read the pseudo code?

Thank you so much!

Best regards!

Hiroshi