1. BF-tree
2. Jeroen Baert . 2018 . Libmorton: C + + Morton Encoding/Decoding Library. https://github.com/Forceflow/libmorton. Jeroen Baert. 2018. Libmorton: C + + Morton Encoding/Decoding Library. https://github.com/Forceflow/libmorton.
3. Multidimensional binary search trees used for associative searching
4. Spatial joins
5. Angjela Davitkova Evica Milchevski and Sebastian Michel. 2020. The ML-Index: A Multidimensional Learned Index for Point Range and Nearest-Neighbor Queries. In EDBT. 407--410. Angjela Davitkova Evica Milchevski and Sebastian Michel. 2020. The ML-Index: A Multidimensional Learned Index for Point Range and Nearest-Neighbor Queries. In EDBT. 407--410.