A great place to start looking for information on Regional Health Information Organizations (RHIOs), also know as Health Information Exchanges (HIEs), is the Healthcare Information and Management Systems Society (HIMSS) website.
Liang, H. (2015). Final review: Coastal Connect Health Information Exchange key findings on value for providers to participate. Retrieved from http://coastalconnect.org/wp-content/uploads/2017/02/final-white-paper-dr-liang.pdf
Phillips, A. B., Wilson, R. V., Kaushal, R., & Merrill, J. A.. (2013). Implementing health information exchange for public health reporting: A comparison of decision and risk management of three regional health information organizations in New York state. Journal of the American Medical Informatics Association, 21(e1), e173-e177. Retrieved from https://academic.oup.com/jamia/article/21/e1/e173/791649
Rural Health IT. (n.d.). Overlay Regional Health Information Exchange (HIE) systems: The sustainable business model for health care information technology in the United States. Retrieved from https://ruralhealthit.com/regional-health-information-exchange-hie-systems/