Andersson, Björn, Kenny Bränberg, and Marie Wiberg. “Performing the Kernel Method of Test Equating With the Package Kequate”. Journal of Statistical Software 55, no. 6 (October 22, 2013): 1–25. Accessed December 4, 2021. https://www.jstatsoft.org/index.php/jss/article/view/v055i06.