If you use the Android or Desktop version of Firefox, there are several archival add-ons that you might find useful.
Note that not all of the following add-ons have official Android support, despite likely functioning without issue. To solve this issue for any given add-on for Firefox on Android, a good solution I've found is to switch to Iceraven, a fork that re-enables xpi add-on support.
Useful for viewing the archived version of a page from several archival sources, including the Internet Archive's Wayback Machine.
The official Wayback Machine add-on, providing several Wayback Machine utilities for the current browser page, along with context menu integration.
Users specifically interested in page archival may want to use the archive-webextension add-on in addition to or instead of it, as it provides additional archival options, such as keyboard shortcut support. A similar extension for archiving pages to archive.today instead is Archive Page.
Haven't tried this extension myself, but it seems useful for retaining access to rented books beyond the limited time period the Internet Archive provides.
It seems to output books in PDF format, with epub conversions not being effective according to a user review. That's likely due to many of the reference materials on the Internet Archive simply being scans of variable quality, and therefore—even with the automatic OCR the Internet Archive does to enable book searches—text accuracy for epub conversions likely varies from book to book.