@article{J. Butterfield2016, author = "Bradley J. Butterfield and Julio L. Betancourt and Raymond M. Turner and John M. Briggs", title = "{Appendix A. Correlation matrix and standard deviations.}", year = "2016", month = "8", url = "https://wiley.figshare.com/articles/dataset/Appendix_A_Correlation_matrix_and_standard_deviations_/3544607", doi = "10.6084/m9.figshare.3544607.v1" }