1. United States Census Bureau.Census Urban and Rural Classification and Urban Area Criteria.2010.https://www.census.gov/programs‐surveys/geography/guidance/geo‐areas/urban‐rural/2010‐urban‐rural.html. Accessed December 2 2019.
2. BishawA PoseyKG.A Comparison of Rural and Urban America: Household Income and Poverty.https://www.census.gov/newsroom/blogs/random‐samplings/2016/12/a_comparison_of_rura.html. Accessed August 21 2017.
3. Rural health;Health Aff,2019
4. National Organization of State Offices of Rural Health.About Rural Health in America.2018.https://nosorh.org/about‐rural‐health‐in‐america/. Accessed December 2 2019.