魏桂东. (2009). 节约的都是利润: What you have saved is your profit. 石油工业出版社.
Dyfyniad Arddull Chicago魏桂东. 节约的都是利润: What You Have Saved Is Your Profit. 石油工业出版社, 2009.
Dyfyniad MLA魏桂东. 节约的都是利润: What You Have Saved Is Your Profit. 石油工业出版社, 2009.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.