求助两篇英文文献，一篇是万方数据库的，一篇是Elsevier的
1.《A survey on energy consumption in rural households in the fringes of Xian city》 ，Yutaka Tonooka, Jiaping Liu, Yasuhiko Kondou, Yadong Ning and Oki Fukasawa；
2.《The influence of using biogas digesters on family energy consumption and its economic benefit in rural areas—comparative study between Lianshui and Guichi in China》，Wang Xiaohua；Di Chonglan；Hu Xiaoyan；Wu Weiming；Jiang Xiaoping；Jiang Shangyun