Willoughby, E. F. (1893). Handbook of public health and demography ([3d ed.].). Macmillan.
Cita Chicago Style (17a ed.)Willoughby, Edward F. Handbook of Public Health and Demography. [3d ed.]. London: Macmillan, 1893.
Cita MLA (8a ed.)Willoughby, Edward F. Handbook of Public Health and Demography. [3d ed.]. Macmillan, 1893.
Precaución: Estas citas no son 100% exactas.