求两篇文章：
1.Richard, Sundaresan,A continuous time equilibrium model of forward prices and futures prices in a multigood economy，J Fin Econ 9 (december 1981): 347-72
2.S. M., Turnbull, Swaps: A zero sum game, Fin. Mgmt 16(1)(Spring 1987): 15-21.
谢谢