title: Commentary: Can 'many weak' instruments ever be 'strong'?
authors.affiliation: Department of Health Sciences, University of Leicester and Department of Mathematics, University of Bristol, Bristol, UK.
authors.forename: Nuala A
authors.initials: NA
authors.lastname: Sheehan
authors.forename: Vanessa
authors.initials: V
authors.lastname: Didelez
mesh_terms: D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D014644:Genetic Variation; D055106:Genome-Wide Association Study; D006801:Humans; D008297:Male; D057182:Mendelian Randomization Analysis