Duffy, J. (1968). A history of public health in New York City, 1625-1866. Russell Sage Foundation.
Dyfyniad Arddull ChicagoDuffy, John. A History of Public Health in New York City, 1625-1866. New York: Russell Sage Foundation, 1968.
Dyfyniad MLADuffy, John. A History of Public Health in New York City, 1625-1866. Russell Sage Foundation, 1968.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.