Park EM, Deal AM, Yopp JM, Edwards TP, Wilson DJ, Hanson LC, Rosenstein DL. End-of-life experiences of mothers with advanced cancer: perspectives of widowed fathers. BMJ Support Palliat Care. 2016 Dec;6(4):437-44. doi: 10.1136/bmjspcare-2015-000976
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.