Reference Grammar (seminars themes taken from here)
And this is the one grammar that rules all (activities will be taken from here). Attention: this is the first edition. Buying the second one is more than desirable.
(to open Djvu files follow the instructions - http://pcinfobrasil.blogspot.com/2007/10/como-converter-djvu-para-pdf.html
Practice exercises must be copied from folder at the university.
All the best,
PS: just for fun...if it is...