IMPROVED GM（1,1）MODEL AND APPLICATION IN NATURAL GAS DEMAND FORECASTING OF SICHUAN PROVINCE
MAO Wen-jin ZHENG Shou-chun
西南石油大学学报(社会科学版) . 2010, (6): 19 -21 .  DOI: 10.3863/j.issn.1674-5094.2010.06.003