The Housing First Model (HFM) fidelity index: designing and testing a tool for measuring integrity of housing programs that serve active substance users
Substance Abuse Treatment Prevention and Policy (2013) - Comment
pubmed: 23641860  doi: 10.1186/1747-597x-8-16  issn: 1747-597x 

Dennis P Watson, John Orwat, Dana E Wagner, Valery Shuman, Randi Tolliver