After tumbling 11.1% in March, bookstore sales had a small rebound in April, increasing 1.5% over April 2002, to $984 million, according to preliminary estimates from the U.S. Census Bureau. Sales for the entire retail segment increased 4.4% in April. For the first four months of the year, bookstore sales were down 1.5%, to $5.01 billion. Sales for all of retail were up 4.3% in the January-through-April period.