APA Style 6th Edition Blog: Pluralize Numbers …
Nov 21, 2013 · Just as with numbers, don’t include an apostrophe when pluralizing abbreviations. For example, when pluralizing an acronym, such as “CV” for “curriculum vitae,” all you need to do is add an s to the end, as in “CVs.”. This rule also applies to standalone letters, as in “The students all received As.”.
DA: 23 PA: 23 MOZ Rank: 38