Riley, B. ., Smith, D. ., & Baigent, M. . (1969). Mindfulness and Acceptance-Based Group Therapy: An Uncontrolled Pragmatic Pre-Post Pilot Study in a Heterogeneous Population of Female Prisoners. International Journal of Offender Therapy and Comparative Criminology, 63(15-16), 2572-2585. https://doi.org/10.1177/0306624X19858487 (Original work published 1969)