https://cy.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/populationestimates/methodologies/userguidetocensus2021origindestinationdataenglandandwales
Canllaw defnyddiwr ar ddata tarddiad-cyrchfan Cyfrifiad 2021, Cymru a Lloegr - Office for National...
Supporting information for origin-destination data from Census 2021 in England and Wales, including how to access and use public, safeguarded and secure...