Help Please...

I am studying some controversial non-profit groups and would like to find 
out who their major donors/funders are (foundations, corporations, etc.). 
 Does anyone have any ideas on how I would find out this information.  Is 
this information available somewhere?  The groups are both 501(c)3 and 
501(c)4.  Because of the controversial nature of my research it is not as 
simple as just asking them.  

Would appreciate any information,

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Carina A. Bandhauer
Doctoral Candidate
Department of Sociology
Binghamton University
State University of New York
Binghamton NY  13902-6000

Office:    (607) 777-6337 (no message)
VoiceMail: (607) 777-2203
Fax:       (607) 777-4197
Email:     br00162@binghamton.edu
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