title: Pfizer and Allergan abandon merger after US tax loophole is closed.
authors.affiliation: The BMJ.
authors.forename: Zosia
authors.initials: Z
authors.lastname: Kmietowicz
mesh_terms: D004345:Drug Industry; D006801:Humans; D013660:Taxes / Q000331:legislation & jurisprudence*; D014481:United States