LIU, Q. and QIAN, Q. 2024. Research on the Efficiency of Major Airports in China’s Six Major Airport Cluster: Based on Common Frontier Super-Efficiency DEA and Malmquist Method. Promet - Traffic&Transportation. 36, 5 (Oct. 2024), 885–901. DOI:https://doi.org/10.7307/ptt.v36i5.609.