Jurincic-Winkler, C., von der Kammer, H., Horlbeck, R., Klippel, K. F., Pixberg, H. U., & Scheit, K. H. (1993). Clinical evaluation of a new prostate-specific antigen sandwich ELISA which employs four monoclonal antibodies directed at different epitopes of prostate-specific antigen. European Urology, 24(4), 487-491.