That depends on what you mean? Do you want something that looks authentic, or do you want something fun with boomerangs, and star-bursts and that ilk? Vintage, or retro, there's a big difference! I think for either you should look in your yellow pages for upholstery shops. For retro, you can find samples on-line, something like this:
A word of advice though, look for subdued colors in a print. Just because you think something looks totally boss, as a sample, like paint, once you get it in with the rest of your furniture, you might find yourself thinking WTF was I thinking. Make sure the colors on the print harmonize with most of the colors in your room:
Another thing to think about is, if it's too fun, it might be thought of as too juvenile looking. Remember, you're trying to make lasting statement in purchasing something you're investing your time in money in, and not a passing fad. Sometimes I see people with furniture the equivalent of Milly Vanilly...
It looks super cool for a while, and then one day it looks like a laps in rational all thinking...then you have to redo it all over again!
Look for something with lasting power, like Les Paul & Mary Ford: