APA Citation

Knopf, K. Ab wheel workouts: 50 exercises to stretch and strengthen your abs, core, arms, back and legs.

Chicago Style Citation

Knopf, Karl. Ab Wheel Workouts: 50 Exercises to Stretch and Strengthen Your Abs, Core, Arms, Back and Legs.

MLA Citation

Knopf, Karl. Ab Wheel Workouts: 50 Exercises to Stretch and Strengthen Your Abs, Core, Arms, Back and Legs.

Warning: These citations may not always be 100% accurate.