FunkJ. L., & RoggeR. D. (2007). Testing the ruler with item response theory: Increasing precision of measurement for relationship satisfaction with the Couples Satisfaction Index. Journal of Family Psychology, 21, 572–583. https://doi.org/10.1037/0893–3200.21.4.572.
2.
RoggeR. D., FinchamF. D., CrastaD., & ManiaciM. R. (2017). Positive and negative evaluation of relationships: Development and validation of the Positive–Negative Relationship Quality (PN–RQ) scale. Psychological Assessment, 29, 1028–1043. https://doi.org/10.1037/pas0000392.