R. Koopman

A new correlation coefficient between categorical, ordinal and interval variables with Pearson characteristics

S. Klous, R. Koopman, M. Baak, 2018, Comput. Stat. Data Anal..

An SPSS Macro to Compute Confidence Intervals for Pearson’s Correlation

R. Koopman, B. Weaver, R. Koopman, 2014 .