The chances are it's a vintage dress so you may not find one the same. You might find something similar from Stop Staring! or Betty Page Clothing. I'd have a look and link but Stop Staring! have soooo many designs it's easier (especially for me) if you have a Google and browse for yourself. You could also try looking on the Pinupgirlclothing.com website.
Failing that, commission a dressmaker to copy it for you.