（1）Title:Dynamically Consistent Oil Import Tariffs
Author:Karp & Newbery
Volume(issue): 25(1)
link:http://www.jstor.org/pss/135707

（2）Title:Optimal oil import tariffs: An international perspective for the 1980s
Author:Kline, David M., Weyant, John P.
Volume(Issue): 11(2)
Pages: 101-118
link:http://www.sciencedirect.com/science/article/pii/0301421583900241

（3）Title: OPEC and The U.S. Oil import tariff.
Author: Karp & Newbery
Volume(Year): 101(1991)
Pages: 303-313
link:http://www.jstor.org/pss/2233820