Kalman, Rudolf E., 1930-2016 and Los, Cornelis A., 1951-. "The Prejudices of Least Squares, Principal Components and Common Factor Schemes, Research Paper no. 8701," Research Papers (Federal Reserve Bank of New York) (February 1987). https://fraser.stlouisfed.org/title/6570/item/707974, accessed on January 20, 2026.