Encoding and Operation for the Planar Aperture 4 Hexagon Grid System
WANG Rui, BEN Jin, DU Lingyu, ZHOU Jianbin, LI Zhuxin
Acta Geodaetica et Cartographica Sinica . 2018, (7): 1018 -1025 .  DOI: 10.11947/j.AGCS.2018.20170374