Enid Blyton

The Secret Series

Secret Island

The Secret Of Spiggy Holes

The Secret Mountain

The Secret Of Killimooin

The Secret Of Moon Castle

The Adventurous Four Duology

The Adventurous Four

The Adventurous Four Again

The Famous Five Series

Five On a Treasure Island (1942)

Five Go Adventuring Again (1942)

Five Run Away Together (1944) aka Five Run Away to Danger

Five Go to Smuggler’s Top (1945)

Five Go Off in a Caravan (1946)

Five On Kirrin Island Again (1947)

Five Go Off to Camp (1948) or Five on the Track of a Spook Train

Five Get Into Trouble (1949) Five Caught in a Treacherous Plot

Five Fall Into Adventure (1950)

Five On a Hike Together (1951) 

Five Have A Wonderful Time

Five Go Down To The Sea (1953)

Five Go to Mystery Moor (1954)

Five Have Plenty of Fun (1955)

Five On a Secret Trail (1956)

Five Go to Billycock Hill (1957)

Five Get Into a Fix (1958)

Five On Finniston Farm (1960)

Five Go to Demon’s Rocks (1961)

Five Have a Mystery to Solve (1962)

Five Are Together Again (1963)

The Adventure Series 

The Island Of Adventure

The Castle Of Adventure

The Valley Of Adventure

The Sea Of Adventure

The Mountain Of Adventure

The Ship Of Adventure

The Circus Of Adventure

The River Of Adventure

The Five Find Outers Series aka The Mystery Series

The Mystery Of The Burnt Cottage

The Mystery Of The Disappearing Cat

The Mystery Of The Secret Room

The Mystery Of The Spiteful Letters

The Mystery Of The Missing Necklace

The Mystery Of The Hidden House

The Mystery Of The Pantomime Cat

The Mystery Of The Invisible Thief

The Mystery Of The Vanished Prince

The Mystery Of The Strange Bundle

The Mystery Of Holly Lane

The Mystery Of The Missing Man

The Mystery Of the Strange Messages

Mystery Of The Banshee Towers