diff --git a/README.md b/README.md
index beef4dff593c2f667884726e0f4a14cdd52345ee..1d6f88dbd6f4667e696488c8c54720ad3c953295 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@ This repository contains OpenAPIs descriptions for the interfaces specified in E
 
 ## Online resources
 
-
+* [Specification document](https://www.etsi.org/deliver/etsi_gs/MEC/001_099/028/02.01.01_60/gs_MEC028v020101p.pdf)
 * [Navigate the API in the browser](https://forge.etsi.org/swagger/ui/?url=https://forge.etsi.org/gitlab/mec/gs028-wai-api/raw/stf593/WlanInformationApi.yaml).
 * [Edit the API online](https://forge.etsi.org/swagger/editor/?url=https://forge.etsi.org/gitlab/mec/gs028-wai-api/raw/stf593/WlanInformationApi.yaml).