Feinstein, A R The fragility of an altered proportion: a simple method for explaining standard errors. [electronic resource] - Journal of chronic diseases 1987 - 189-92 p. digital Publication Type: Journal Article; Research Support, Non-U.S. Gov't ISSN: 0021-9681 Standard No.: 10.1016/0021-9681(87)90152-4 doi Subjects--Topical Terms: Sampling StudiesStatistics as Topic