Simplify the following text for a Grade 9 native English-speaking person.
Original: The 2007 MacropÃ dia has 699 in-depth articles , ranging in length from 2 to 310 pages and having references and named contributors .
Simplified: The 2007 MacropÃ dia has 699 detailed articles , which can be as short as 2 pages and as long as 310 pages , and having references and named writers .