To successfully access titles when connecting off campus you should use the Publication Finder link in LibrarySearch. You can also find titles by searching directly from individual databases in the portal e.g. Ebook Central, EBSCO eBooks, VleBooks or from Moodle links provided by your lecturer.
When connecting off campus (or from a wireless connected laptop within the University), you may need to sign in via an institutional access login page and multi-factor authentication where you will need to select the University name from a list of institutions first.