You can find this exercise on page 116 of the book Synergistic Golf.
Exercise Type: STRENGTH
Exercise Category: HIPS, LEGS - FEET, POWER PRODUCTION, STRENGTH
Stand with feet wider than hips and toes aiming diagonally outward. Inhale and sit back with your hips as you bend your knees into a squat. Make sure knees stay over heels not outside toes. Exhale return back to standing keeping abdominals tight and gluteals squeezed. Repeat 10-20x.