Official, copyrighted versions of the standard are available for purchase and download through authorized webstores. , as these often contain outdated versions or security risks.
Regional versions such as BS EN IEC 60099-5 or SIST EN IEC 60099-5 can be found on the BSI Knowledge base or the iTeh Standards Store . iec 600995 pdf link
Specifically for overhead transmission lines, governed by IEC 60099-8. Key Updates in the 2018 Edition Official, copyrighted versions of the standard are available