Fergusson, D M The effects of lead levels on the growth of word recognition in middle childhood. [electronic resource] - International journal of epidemiology Oct 1993 - 891-7 p. digital Publication Type: Journal Article; Research Support, Non-U.S. Gov't ISSN: 0300-5771 Standard No.: 10.1093/ije/22.5.891 doi Subjects--Topical Terms: ChildCognition Disorders--chemically inducedCohort StudiesConfounding Factors, EpidemiologicDentin--chemistryEnvironmental ExposureHumansLead--analysisLead Poisoning--epidemiologyLearning Disabilities--chemically inducedNew Zealand--epidemiologySelection Bias