Нашёл 25 млн ответов for 'OS X High Sierra'.
https://en.m.wikipedia.org/wiki/MacOS_High_Sierra
https://en.wikipedia.org/wiki/MacOS_High_Sierra
https://en.wikipedia.org/wiki/MacOS_version_history
https://isoriver.com/mac-os-high-sierra-10-13-iso/
https://apple.fandom.com/wiki/MacOS_High_Sierra
https://www.tonymacx86.com/forums/high-sierra-desktop-guides.191/
https://www.tonymacx86.com/threads/how-to-create-a-macos-high-sierra-public-beta-installation-usb.225520/
https://www.tonymacx86.com/
https://themacgo.com/macos-high-sierra-10-13-6-dmg-mac-free-download-iso/