Об этом дополнении
OCLC WorldCat library catalog, a Mozilla add-on to directly find items in 10,000 different libraries. From your search bar, Look among WorldCat's 1.5 billion items, the largest collection in the world. It contains books, articles, DVDs, CDs, and other media. WorldCat will show descriptions and exportable citations for your item, and point/link you the nearest library with a copy.