An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Campbell I, Royle G, Coddington R, Herbert A, Rubin C, Taylor I, Guyer P.Campbell I, et al.Ann R Coll Surg Engl. 1993 Jan;75(1):13-7.Ann R Coll Surg Engl. 1993.PMID: 8422137Free PMC article.
Smallwood J, Khong Y, Boyd A, Guyer P, Herbert A, Cooke T, Taylor I.Smallwood J, et al.Ann R Coll Surg Engl. 1984 Jul;66(4):267-9.Ann R Coll Surg Engl. 1984.PMID: 6742740Free PMC article.