OMS. Basis epidemiology. Geneva: OMS.
Dyfyniad Arddull ChicagoOMS. Basis Epidemiology. Geneva: OMS.
Dyfyniad MLAOMS. Basis Epidemiology. Geneva: OMS.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.
OMS. Basis epidemiology. Geneva: OMS.
Dyfyniad Arddull ChicagoOMS. Basis Epidemiology. Geneva: OMS.
Dyfyniad MLAOMS. Basis Epidemiology. Geneva: OMS.