Books with Sequels

The Princess and the Goblin/The Princess and the Curdie
Eight Cousins/Rose In Bloom
Daddy Long Legs/Dear Enemy

Trilogies

100 Cupboards
Ashtown Burials Books
The Outlaws of Time
Little Women
Nurse Matilda
The Lord of the Rings
Noisy Village Books
CS Lewis’s Space Trilogy
Shiloh (Cautionary)
The Mitchells Series
The Mad Scientists Club
The Wilderking Trilogy
Emily of New Moon

Series with 4 or more

Frances Books
The Chronicles of Narnia
The Mistmantle Chronicles
The Growly Books
The Wingfeather Saga (Wingfeather Tales makes it 5)
The Little Britches Books
Chitty Chitty Bang Bang
Alvin Fernald Books
Henry Reed Books
Dinotopia Books
Theodore Boone, Kid Lawyer
Betsy-Tacy
Grandmother’s Attic
The Cobble Street Cousins
The Mysterious Benedict Society
All of a Kind Family
Anne of Green Gables series
Harold and the Purple Crayon (picture books)
Billy and Blaze (for young readers)

Series with 10 or more

The Green Ember Books
Danny Dunn Books
Thornton Burgess Books
The Black Stallion

Series with more than 1 author

Chitty Chitty Bang Bang
The Wingfeather Saga (Wingfeather Tales)
Danny Dunn