APA   Click to copy
Vowles, K. E., & Sorrell, J. T. (2007). Life with chronic pain: An acceptance-based approach (therapist guide and patient workbook). Unpublished Manuscript.

Chicago/Turabian   Click to copy
Vowles, Kevin E, and John T Sorrell. “Life with Chronic Pain: An Acceptance-Based Approach (Therapist Guide and Patient Workbook).” Unpublished manuscript (2007).

MLA   Click to copy
Vowles, Kevin E., and John T. Sorrell. “Life with Chronic Pain: An Acceptance-Based Approach (Therapist Guide and Patient Workbook).” Unpublished Manuscript, 2007.

@article{vowles2007a,
  title = {Life with chronic pain: An acceptance-based approach (therapist guide and patient workbook)},
  year = {2007},
  journal = {Unpublished manuscript},
  author = {Vowles, Kevin E and Sorrell, John T}
}