diff --git a/examples/librispeech/asr2/README.md b/examples/librispeech/asr2/README.md
index 5bc7185a9..26978520d 100644
--- a/examples/librispeech/asr2/README.md
+++ b/examples/librispeech/asr2/README.md
@@ -1,6 +1,6 @@
 # Transformer/Conformer ASR with Librispeech ASR2
 
-This example contains code used to train a Transformer or [Conformer](http://arxiv.org/abs/2008.03802) model with [Librispeech dataset](http://www.openslr.org/resources/12) and use some functions in kaldi.
+This example contains code used to train a [u2](https://arxiv.org/pdf/2012.05481.pdf) model (Transformer or [Conformer](https://arxiv.org/pdf/2005.08100.pdf) model) with [Librispeech dataset](http://www.openslr.org/resources/12) and use some functions in kaldi.
 
 To use this example, you need to install Kaldi first.