Update README

README.md

@@ -4,7 +4,6 @@ This repository contains OpenAPIs descriptions for the interfaces specified in E
 
 ## Online resources
 
-* [Specification document](https://www.etsi.org/deliver/etsi_gs/MEC/001_099/028/02.02.01_60/gs_MEC028v020201p.pdf)
 * [Navigate the API in the browser](https://forge.etsi.org/swagger/ui/?url=https://forge.etsi.org/rep/mec/gs028-wai-api/raw/stf606-final/WlanInformationApi.yaml).
 * [Edit the API online](https://forge.etsi.org/swagger/editor/?url=https://forge.etsi.org/rep/mec/gs028-wai-api/raw/stf606-final/WlanInformationApi.yaml).