Hildegarde Withers

1 The Penguin Pool Murder (1931)
2 Murder on Wheels (1932)
3 Murder on the Blackboard (1932)
4 The Puzzle of the Pepper Tree (1933)
5 The Puzzle of the Silver Persian (1934)
6 The Puzzle of the Red Stallion (1936)
     aka The Puzzle of the Briar Pipe
7 The Puzzle of the Blue Banderilla (1937)
8 The Puzzle of the Happy Hooligan (1941)
9 Miss Withers Regrets (1947)
10 Four Lost Ladies (1949)
11 The Green Ace (1950)
     aka At One Fell Swoop
12 Nipped in the Bud (1951)
13 Cold Poison (1954)
     aka Exit Laughing
14 Hildegarde Withers Makes the Scene (1969)

The Riddles of Hildegarde Withers (1947)
The Monkey Murder (1950)
Uncollected Riddles (2002)
Final Riddles? (2021)