Can't find the manuals page (bad link)

The following is a bad link: https://premium.wpmudev.org/all-wpmu-dev-manuals/

It was included in the following paragraph within one of my welcome e-mails from WPMU: "Extensive, detailed, updated manuals - We're constantly updating our manuals covering every aspect of installation, configuration and management of WordPress, Multisite and BuddyPress installations."

Could you provide for me the correct link?