1. Comparative health system performance publications.https://www.ahrq.gov/chsp/publications/index.html
2. AHRQ Compendium of US Health Systems.https://www.ahrq.gov/chsp/data‐resources/compendium.html
3. Consolidation of providers into health systems increased substantially, 2016–18;Furukawa MF;Health Affairs,2020
4. A comprehensive theory of integration;Singer SJ;Medical Care Res Rev,2020
5. Organizational integration, practice capabilities and outcomes in clinically complex medicare beneficiaries;Colla C;Health Serv Res,2020