Cates SC, Kosa KM, Karns S, Godwin SL, Speller-Henderson L, Harrison R, Ann Draughon F. Food safety knowledge and practices among older adults: identifying causes and solutions for risky behaviors. J Nutr Elder. 2009 Apr;28(2):112-26. doi: 10.1080/01639360902949986
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.