Challenge
Challenging behaviour
Challenging Impossibility
Challenging Heights
Challenging the Chip
Remote Applications in Challenging Environments
Challenging Times
United States v. Students Challenging Regulatory Agency Procedures
Maze: Solve the World's Most Challenging Puzzle
Hum Honorary Most Challenging Subject Award
Beyond Queer
Educational Action Challenging Homophobia
In Praise of Slow
CHAMP (satellite)
In the Shadow of the Moon (book)
The Slow Professor
Darshan (Kannada actor)
Arab Chiefs Challenging each other to Single Combat under the Ramparts of a City
Richard Milton (author)
Q*bert
Grievance studies affair