The annual Bryn Mawr-Wellesley Book Sale will continue through March 21 at Princeton Day School., Started in 1931, the sale is the longest-running and largest used-book-selling endeavor on the East Coast, according to the group’s website. It is renowned for not only the number of books but also the quality it offers., Proceeds from the sale go to scholarships for local students. The organization also recycles a large number of books, provides a place for book lovers to buy good-quality volumes at reasonable prices and helps those who want to reduce the sizes of their libraries., Opening day continues through 5 p.m. today. Tickets for today are $25. Hours for the rest of the show are Saturday, March 18, from 10 a.m. to 7 p.m.; Sunday, March 19, from 10 a.m. to 5 p.m.; Monday, March 20 (Half-Price Day) from 10 a.m. to 6 p.m.; and Tuesday, March 21 (Box Day) from 10 a.m. to 3 p.m., Princeton Day School is at 650 Great Road in Princeton. Park and enter the building at the northwest end. Look for posters hung in the windows. Do not use the rink driveway entrance and do not park in the fire lane. The organization is not responsible for tickets or towing charges.