Skoog, L., S. Humla, M. Axelsson, M. Frost, A. Norman, B. Nordenskjöld, and A. Wallgren. “Estrogen Receptor Levels and Survival of Breast Cancer Patients: A Study on Patients Participating in Randomized Trials of Adjuvant Therapy”. Acta Oncologica 26, no. 2 (January 1, 1987): 95–100. Accessed May 26, 2026. https://medicaljournalssweden.se/actaoncologica/article/view/32429.