TY - PROGRESS IN GEOGRAPHY A1 - T1 - Y1 - 1993-08-24 00:00:00.0 JF - PROGRESS IN GEOGRAPHY JO - PROGRESS IN GEOGRAPHY SP - 6 EP - 10 VL - 12 IS - 3 UR - {https://www.progressingeography.com/EN/10.11820/dlkxjz.1993.03.002} N1 - 10.11820/dlkxjz.1993.03.002 ER -