Harley, N H The rapid estimation of radon daughter working levels when daughter equilibrium is unknown. [electronic resource] - Health physics Jul 1969 - 109-14 p. digital Publication Type: Journal Article ISSN: 0017-9078 Standard No.: 10.1097/00004032-196907000-00011 doi Subjects--Topical Terms: Air Pollution, RadioactiveAlpha ParticlesFiltrationMethodsRadiometryRadonTechnology, Radiologic