My primary work at Wikipedia has been improving the quality of the reference section of articles. While this includes adding references to "under-referenced" articles, it more commonly means improving the existing references, including (but not limited to) formatting inline citations, combining duplicate references, finding archive links for dead urls, bringing references in compliance with the manual of style, creating separate sections for notes, completing incomplete references, correcting references that point to a mistaken source, and removing inappropriate references. Here are some examples:
I am a good article reviewer and have currently reviewed over seventy articles. Look here for the full list. Here are some articles I've recently reviewed:
I am also a featured article reviewer and have currently reviewed less than ten articles. Look here for a full list. Here are some articles I've recently reviewed: