http://dl.acm.org/citation.cfm?id=2398426 http://dl.acm.org/citation.cfm?id=2396825 http://dl.acm.org/citation.cfm?id=2396826 http://dl.acm.org/citation.cfm?id=2398494 http://dl.acm.org/citation.cfm?id=2398557 http://dl.acm.org/citation.cfm?id=2398563 http://dl.acm.org/citation.cfm?id=2398523 http://dl.acm.org/citation.cfm?id=2398692 http://dl.acm.org/citation.cfm?id=2398521 http://dl.acm.org/citation.cfm?id=2398591&dl=ACM&coll=DL&CFID=354549565&CFTOKEN=55868162 http://dl.acm.org/citation.cfm?id=2398636 http://dl.acm.org/citation.cfm?id=2398681 http://dl.acm.org/citation.cfm?id=2398528