Simplify the following text for a Grade 8 native English-speaking person.
Original: Her other novels include Hangsaman ( 1951 ) , The Bird 's Nest ( 1954 ) , The Sundial ( 1958 ) and The Haunting of Hill House ( 1959 ) , regarded by many as one of the important horror novels of the 20th Century .
Simplified: Her other novels include Hangsaman ( 1951 ) , The Bird 's Nest ( 1954 ) and The Sundial ( 1958 ) . The Haunting of Hill House ( 1959 ) is regarded by many , including Stephen King , as one of the important horror novels of the 20th century .