[caption id="attachment_329658" align="aligncenter" width="600" caption="Wonder Girls at Billboard.com's studio for Mashup Mondays"][/caption] Yesterday, the Wonder Girls unveiled their beautiful cover of B.o.B. feat. Bruno Mars "Nothin' On You" for Billboard's Mashup Mondays. Now, the Wonder Girls official YouTube channel gives you a special glimpse at the behind the scenes look into the practice and production for the beautiful cover. Check it out below!