diff --git a/README.md b/README.md
index 8193272..082928b 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,7 @@
 [![GitHub release](https://img.shields.io/github/release/suutaku/go-bbs?include_prereleases=&sort=semver&color=blue)](https://github.com/suutaku/go-bbs/releases/)
 [![License](https://img.shields.io/badge/License-MIT-blue)](#license)
 [![dependency - github.com/suutaku/bls12381](https://img.shields.io/badge/dependency-github.com%2Fsuutaku%2Fbls12381-blue)](https://pkg.go.dev/github.com/suutaku/bls12381)
+
  A **BBS++** signature pure go implementation refer to [hyperledger/ursa](https://github.com/hyperledger/ursa.git) (**Rust**) and [heyperledger/aries-framework-go](https://github.com/hyperledger/aries-framework-go.git) (**Without Blind sign**).