网络资料参考文献怎么写英文

(Reference) 【1】 Author: Guoxing Wang Title: "Learn to sell Automobile in seven days," Publisher: Mechanical Industry Press Publication date: January 1, 2009 【2】Author: Liu TiGuo title: "the Right Way to Sell Automobile- N-selling Skills from master sellers "Publisher:People's Posts & Telecoms Press Publication date: March 2009

本来应该是写页码的，如102-105,表示在期刊的第102到105页但是NA=not available，表示页码未知，不能确定最终页码的