Simplify the following text for a Grade 14 native English-speaking person.
Original: Consisting of some 3,000 volumes , the collection includes manuscripts , notebooks and scrapbooks , periodicals in which Cabell 's essays , reviews and fiction were published , his correspondence with noted writers including H. L. Mencken , Ellen Glasgow , Sinclair Lewis and Theodore Dreiser , correspondence with family , friends , editors and publishers , newspaper clippings , photographs , periodicals , criticisms , printed material , publishers ' agreements and statements of sales .
Simplified: The collection includes some 3,000 volumes , manuscripts , notebooks and scrapbooks , periodicals , letters ( including conversations with noted writers such as H.L. Mencken , Ellen Glasgow , Sinclair Lewis and Theodore Dreiser ) , newspaper clippings , photographs , criticisms , printed material , publishers ' agreements and statements of sales .