Evolution Analysis on Droughts in Northeast China During 1961-2012 Based on SPEI
GAO Bei，JIANG Tong，SU Buda，ZHU Xianyun，WANG Yanjun
Chinese Journal of Agrometeorology . 2014, (06): 656 -662 .  DOI: 10.3969/j.issn.1000-6362.2014.06.008