Mark S. Henriksen

1995

• [ ] The Firm Cross Trainers - Firm Strength (Writer) 
• [ ] The Firm Cross Trainers - Firm Cardio (Writer) 

1997

• [ ] The Firm Basics - Sculpting with Weights (Writer) 

1998

• [ ] The Firm Parts - Sculpted, Buns, Hips & Thighs (Writer) 
• [ ] The Firm Parts - Tough Tape (Writer) 

2003

• [ ] The Firm - Maximum Body Sculpting (Writer) 

2012

• [ ] The Firm - Body Sculpting Basics (Writer) 
• [ ] The Firm - Time Crunch (Writer) 

2014

• [ ] The Firm Basics - Abs, Buns & Thighs (Writer) 

????

• [ ] The Firm Basics - Fat Burning (Writer)