Quad list quad trees: a geometrical data structure with improved performance for large region queries
L. Weyten, Wim De Pauw · IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems · 1989
A data structure is presented for the storage of graphical information. It is a modified multiple storage quad tree, with four lists in each leaf quad. A substantial improvement is obtained for region queries, in particular on large windows, and for tree traversal. On the other hand, only an insignificant increase of memory requirement is noticed in particular situations. The method is not complicated, so it can easily be programmed.>