Mumbai, Dec 24 (ANI): Bollywood actress Kangana Ranaut was spotted launching Vibha Singh’s book 'A Convenient Culprit' at Landmark Store in Mumbai. On the occasion Kangana said that it was a bit unusual for her to unveil a book but she was happy to do it. Dressed for the occasion Kangna looked stunning in a formal black skirt with a check shirt. The actress will next be seen in ‘Queen’ which is slated for a 28th February release.