TY - Acta Geographica Sinica A1 - LIU Yu T1 - Revisiting several basic geographical concepts:A social sensing perspective Y1 - 2020-05-22 00:00:00.0 JF - Acta Geographica Sinica JO - Acta Geographica Sinica SP - 564 EP - 575 VL - 71 IS - 4 UR - {https://www.geog.com.cn/EN/10.11821/dlxb201604003} N1 - 10.11821/dlxb201604003 ER -