Most major style guides today support using resources like Perma.cc to supplement online source citations.
BLUEBOOK: The twentieth edition of The Bluebook introduced Rule 18.2.1(d), which encourages the archival of online sources and uses Perma as one example of a "reliable archival tool." The new guideline directs writers and editors to cite online sources by adding a permalink URL in brackets after the original URL at the end of a citation.
The following citation is slightly different, but also appropriate:
CHICAGO MANUAL OF STYLE: In the Chicago Manual of Style (17th Edition), Chapter 14.15 likewise encourages the use of resources like Perma.cc to create a permanent record of any online sources that may change or become difficult to find later on. (This advice is reiterated in 14.207, in relation to proper citation of web pages and websites.)