Hello, I am wondering whether anyone know an elementary reference for Colombeau's theory on the multiplication of distributions? I encountered the problem of the square of Delta function. I need a rigorous treatment of this object. Through my previous question, I notice that Colombeau's theory might help. Thank you in advance for any points. :-)



An elementary introduction of Colombeau's generalized function theory
Sorry for repeating myself, but as you can see on the nLab [here](http://nlab.mathforge.org/nlab/show/distribution#colombeau_10), Colombeau himself has written an elementary introduction to his theory, mainly for people who are interested in applications: 


Jean François Colombeau: "Multiplication of distributions. A tool in mathematics, numerical engineering and theoretical physics."


See this [review](http://www.zentralblatt-math.org/zmath/en/advanced/?q=an:00108533&type=pdf&format=complete) in the Zentralblatt Mathematik. This will also give you a hint if this approach is suitable to your problem (BTW: what is the application you are thinking about?).


