diff --git a/README.md b/README.md
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--- a/README.md
+++ b/README.md
@@ -335,4 +335,4 @@ PaddleSpeech is provided under the [Apache-2.0 License](./LICENSE).
 
 ## Acknowledgement
 
-PaddleSpeech depends on a lot of open source repos. See [references](docs/source/asr/reference.md) for more information.
+PaddleSpeech depends on a lot of open source repos. See [references](docs/source/reference.md) for more information.
diff --git a/docs/source/asr/reference.md b/docs/source/asr/reference.md
deleted file mode 100644
index d3676fff..00000000
--- a/docs/source/asr/reference.md
+++ /dev/null
@@ -1,8 +0,0 @@
-# Reference
-
-We refer these repos to build `model` and `engine`:
-
-* [delta](https://github.com/Delta-ML/delta.git)
-* [espnet](https://github.com/espnet/espnet.git)
-* [kaldi](https://github.com/kaldi-asr/kaldi.git)
-* [wenet](https://github.com/mobvoi/wenet)
diff --git a/docs/source/reference.md b/docs/source/reference.md
new file mode 100644
index 00000000..ac704cb0
--- /dev/null
+++ b/docs/source/reference.md
@@ -0,0 +1,33 @@
+# Reference
+
+We borrowed a lot of code from these repos to build `model` and `engine`, thank for these great work:
+
+* [espnet](https://github.com/espnet/espnet/blob/master/LICENSE)
+- Apache-2.0 License
+- python/shell `utils`
+- kaldi feat preprocessing
+- datapipeline and `transform`
+- a lot of tts model, like `fastspeech2` and GAN-based `vocoder`
+
+* [wenet](https://github.com/wenet-e2e/wenet/blob/main/LICENSE)
+- Apache-2.0 License
+- U2 model
+- Building TLG based Graph
+
+* [kaldi](https://github.com/kaldi-asr/kaldi/blob/master/COPYING)
+- Apache-2.0 License
+- shell/perl/python utils.
+- feature bins.
+- WFST based decoding for LM integration.
+
+* [delta](https://github.com/Delta-ML/delta/blob/master/LICENSE)
+- Apache-2.0 License
+- `engine` arch
+
+* [speechbrain](https://github.com/speechbrain/speechbrain/blob/develop/LICENSE)
+- Apache-2.0 License
+- ECAPA-TDNN SV model
+
+* [chainer](https://github.com/chainer/chainer/blob/master/LICENSE)
+- MIT License
+- Updater, Trainer and more utils.