TY - PROGRESS IN GEOGRAPHY A1 - ZHANG Linxiu T1 - Randomized Controlled Trails: A state-of-art impact evaluation method Y1 - 2013-06-25 00:00:00.0 JF - PROGRESS IN GEOGRAPHY JO - PROGRESS IN GEOGRAPHY SP - 843 EP - 851 VL - 32 IS - 6 UR - {https://www.progressingeography.com/EN/10.11820/dlkxjz.2013.06.001} N1 - 10.11820/dlkxjz.2013.06.001 ER -