Here are some of teh books you can prefer for DHA Preparation Material for Physiotherapist.

Tide's Physical therapy 12th Edition by Ann Thompson

Physical Rehabilitation 6th Edition by Susan B. O'Sullivan (Author)

Muscles: Testing and Function, with Posture and Pain (Kendall, Muscles) Fifth, North American Edition by Florence Peterson Kendall

Clayton's Electrotherapy: Theory and Practice by Angela Forster

Good Luck!