Huajun Chen Bin Lu Yuan Ni Guo Tong Xie Chunying Zhou Jinhua Mi Zhaohui Wu Mashup by Surfing a Web of Data APIs. 1602-1605 2009 2 PVLDB 2 http://www.vldb.org/pvldb/2/vldb09-1033.pdf db/journals/pvldb/pvldb2.html#ChenLNXZMW09