Simple BM25 extension to multiple weighted fields.

@inproceedings{robertson-2004-simple, author = {Stephen E. Robertson and Hugo Zaragoza and Michael J. Taylor}, editor = {David A. Grossman and Luis Gravano and ChengXiang Zhai and Otthein Herzog and David A. Evans}, title = {{Simple BM25 extension to multiple weighted fields}}, booktitle = {{Proceedings of the 2004 ACM CIKM International Conference on Information and Knowledge Management, Washington, DC, USA, November 8-13, 2004}}, pages = {42--49}, publisher = {ACM}, year = {2004}, url = {https://doi.org/10.1145/1031171.1031181}, doi = {https://doi.org/10.1145/1031171.1031181} }