http://www.aaai.org/Library/AAAI/aaai-library.php took me forever to find this and this http://www.aaai.org/ocs/index.php/AAAI/AAAI14/search. Very valuable.
Then we have AAMAS proceedings: http://dl.acm.org/event.cfm?id=RE146&tab=pubs&CFID=454223637&CFTOKEN=11498247.