
Riddle
2013

The Loveliest Riddle
2008

The Riddle of Jaan Niemand
2018

Riddles In Mathematics
2017

The Riddler: Riddle Me This
2013

The Riddle of Fibonacci
2020

Murder, She Wrote: The Celtic Riddle
2003

Riddle Child
2018

Riddle Room
2016

Riddles of the Sphinx
2008

The Shoshani Riddle
2023

Crossword Mysteries: Riddle Me Dead
2021

The Riddle
1984

The Riddle of the Stinson
1988

The Riddle of the Sands
1979

JerryMaya's Detective Agency – The Riddle of the Scorpion
2022

Riddles for a Candy
1978

The Riddle of Einstein
2021

Riddle: Superstitions from the Garbage Can
1989

UFO: An Intriguing Riddle!
2004