Watkins, T. R., Barrett, M. C., & Lewellen, A. (2001). Dual diagnosis: An integrated approach to treatment. Sage Publications.

Watkins, Ted R., Marjie Crow Barrett, and Ara Lewellen. Dual Diagnosis: An Integrated Approach to Treatment. Thousand Oaks, Calif.: Sage Publications, 2001.

Watkins, Ted R., et al. Dual Diagnosis: An Integrated Approach to Treatment. Sage Publications, 2001.