[en] ABS! 50 of the Best Core Exercises to Strengthen, Tone, and Flatten Your Belly. Letsdoyoga.com
[en] The Women's Health Big Book of Abs Rodale Books
[en] How to Get Lean, Strong & Bulletproof Tim Blake
[en] ABS! 50 of the Best Core Exercises to Strengthen, Tone, and Flatten Your Belly. Letsdoyoga.com
[en] The Women's Health Big Book of Abs Rodale Books
[en] How to Get Lean, Strong & Bulletproof Tim Blake