This New York Times series regarding Wal-Mart bribes in Mexico is excellent.

Part I - April 21st, 2012
Wal-Mart Hushed Up a Vast Mexican Bribery Case
Confronted with evidence of widespread corruption in Mexico, top Wal-Mart executives focused more on damage control than on rooting out wrongdoing, an examination by The New York Times found.

Part II - December 17th, 2012
How Wal-Mart Used Payoffs to Get Its Way in Mexico
Wal-Mart de Mexico was an aggressive and creative corrupter, offering large payoffs to get what the law otherwise prohibited, an examination by The New York Times found.