The pdf file (warning: large file) is available here.
The filing claims that the Wisconsin Club for Growth misled the IRS
by claiming $0 on campaign activities in 2011 and 2012 while spending
close to $20 million. They spent $9.1 million on the 2011 and 2012
recall elections and funneling $9.624 million to other groups (some
controlled by WCfG leaders) that spent those funds on political ads.
That spending, the filing concludes, made it clear that WCfG's primary
activity "was to elect political candidates in Wisconsin".
The filing goes on to say that the only candidates supported by that
spending were Republicans indicating the partisan nature of their
spending rather than for the common good of the public.