MUMBAI: E-commerce major Flipkart has been ranked second among top book sellers of the world, according to a survey.Flipkart is the only Indian brand to be ranked among the top five, says the survey report 'Top 40 Global Bookstore Mind Share' (BMS Index).The survey, which assessed both offline as well as online book sellers across the globe, has ranked Flipkart ahead of companies like Barnes & Noble of the United States, FNAC of France, Waterstones of the UK and The Book Depository, also from UK.The results were finalised by standardising data from sources like Wikipedia traffic, Google Books N-Gram and Google search term frequency.The index was based on two factors, the number of people thinking about these stores and its frequency.The research project for BMS Index was led by Paul Xavier McCarthy , Adjunct Professor of University of New South Wales , Australia and author of 'Online Gravity'.Flipkart retails over 30 million books spread across literature, fiction, academic, biographies, business and management and self-help.