title: Needles and haystacks.
authors.affiliation: University of Manchester
authors.forename: Peter
authors.initials: P
authors.lastname: Callery
mesh_terms: D000043:Abstracting and Indexing; D016206:Databases, Bibliographic / Q000706:statistics & numerical data*; D006801:Humans; D016247:Information Storage and Retrieval / Q000379:methods*; D016239:MEDLINE / Q000706:statistics & numerical data; D010371:Pediatric Nursing; D012107:Research Design; D012196:Review Literature as Topic