Blume, Marshall E., Donald B. Keim, and Sandeep A. Patel. “Returns and Volatility of Low-Grade Bonds 1977-1989”. Financial Services Review 1, no. 2 (December 30, 1991): 180. Accessed July 3, 2024. https://openjournals.libs.uga.edu/fsr/article/view/3687.