Bookstore sales fell 4.5% in August, to $1.93 billion, according to preliminary estimates released Tuesday morning by the U.S. Census Bureau. The August decline was the third month in a row bookstore sales had a meaningful drop and sales for the first eight months of 2013 were down 2.6%, to $8.80 billion, compared to the same period in 2012.

Sales for the entire retail segment rose 4.7% in August and were up 4.3% in the eight month period.