the xkcd store

Citation Needed Sticker Pack

With these stickers, you can append a Wikipedia-style [citation needed] to dubious printed statements encountered in real life. They're translucent and come in sheets containing a range of sizes, so they can be affixed to subway ads, product packaging, textbooks, or "free kittens!" fliers making obviously exaggerated claims about cuteness.

Each sheet is 5"x7" and contains 24 stickers.

new things