Digital Trade Feature Map: A New Method for Visualization and Analysis of Spatial Patterns in Bilateral Trade. - Sijing Ye; Changqing Song; Changxiu Cheng; Shi Shen; Peichao Gao; Ting Zhang; Xiaoqiang Chen; Yuanhui Wang; Changjun Wan (ISPRS Int. J. Geo Inf., 2020)