Morgan L, Hawe E, Palmen J, Montgomery H, Humphries SE, Kitchen N. Polymorphism of the heme oxygenase-1 gene and cerebral aneurysms. Br J Neurosurg. 2005;19(4):317-21.
Reed (Earnshaw) SJ, Reed JH. The use of statistical quality control charts in monitoring interviewers. Proceedings of the Survey Research Methods Section, American Statistical Association. 1997 Jan;893-8.