Update README.md

Author: xhluca

README.md

@@ -430,6 +430,8 @@ Similarly, for MSMARCO (8M+ documents, 300M+ tokens), we show the following resu
 
 ## Acknowledgement
 
+* The central idea behind the scoring mechanism in this library is originally from [bm25_pt](https://github.com/jxmorris12/bm25_pt), which was a major inspiration to this project.
+* The API of the [`BM25` class](https://github.com/xhluca/bm25s/blob/main/bm25s/__init__.py) is also heavily inspired by the design of BM25-pt, as well as that of rank-bm25.
 * The multilingual stopwords are sourced from the [NLTK stopwords lists](https://github.com/nltk/nltk/blob/96ee715997e1c8d9148b6d8e1b32f412f31c7ff7/nltk/corpus/__init__.py#L315).
 * The numba implementation are inspired by numba implementations originally proposed by [baguetter](https://github.com/mixedbread-ai/baguetter) and [retriv](https://github.com/AmenRa/retriv).
 * The function `bm25s.utils.beir.evaluate` is taken from the [BEIR library](https://github.com/beir-cellar/beir). It follows the same license as the BEIR library, which is Apache 2.0.