Bookstore sales posted their slowest growth of the year in July, with sales up 4.5% to $1.17 billion, according to preliminary estimates from the U.S. Census Bureau. The 4.5% increase was better than the 3.4% growth rate recorded by the entire retail segment for the month. In the January—July period, bookstore sales increased 8.1%, to $8.93 billion, compared to a 3.1% gain for all of retail.