網址: https://www.researchgate.net/profile/Xuejian-Cao/publication/343731008/figure/fig2/AS:926076758921216@1597805313661/The-schematic-of-sub-grid-routing-processes-in-a-specific-grid-unit-a-UIArelated_Q320.jpg
網址2: https://www.researchgate.net/figure/The-schematic-of-sub-grid-routing-processes-in-a-specific-grid-unit-a-UIArelated_fig2_343731008
