Cita APA (7a ed.)
Porterfield, J. D., & Porterfield, J. D. (1964). Community health in the United States.
Cita estilo Chicago (17a ed.)
Porterfield, John D., y John D. Porterfield. Community Health in the United States. 1964.
Cita MLA (9a ed.)
Porterfield, John D., y John D. Porterfield. Community Health in the United States. 1964.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.