Phenological Changes in Spring in Last 40 Years in North China
HAN Chao1,2,ZHENG Jing-yun1,GE Quan-sheng1(1.Institute of Geographic Science and Natural Resource Research,CAS,Beijing 100101,China;2.Graduate School of Chinese Academy of Sciences)
Chinese Journal of Agrometeorology . 2007, (02): 113 -117 .