Implementation of Smartphone Systems to Improve Quality of Life for People With Substance Use Disorder: Interim Report on a Randomized Controlled Trial oleh David Gustafson Sr, Julie Horst, Deanne Boss, Kathryn Fleddermann, Nora Jacobson, Mathew Roosa, J Charles Ross, Rachel Gicquelais, Olivia Vjorn, Tracy Siegler, Todd Molfenter