1. https://github.com/searchivarius/nmslib.
2. https://github.com/spotify/annoy.
3. L2AP: fast cosine similarity search with prefix L-2 norm bounds;Anastasiu;ICDE,2014
4. The inverted multi-index;Babenko,2012
5. Additive quantization for extreme vector compression;Babenko;CVPR,2014