TY - Acta Geographica Sinica A1 - YANG Shengtian, LIU Changming, SUN Rui T1 - The Vegetation Cover over Last 20 Years in Yellow River Basin Y1 - 2002-11-25 00:00:00.0 JF - Acta Geographica Sinica JO - Acta Geographica Sinica SP - 679 EP - 684 VL - 57 IS - 6 UR - {https://www.geog.com.cn/EN/10.11821/xb200206007} N1 - 10.11821/xb200206007 ER -