Jackson, J. E. (1981). “Principal Components and Factor Analysis, Part 3: What Is Factor Analysis?” Journal of Quality Technology 13:125–130.
Jackson, J. E. (1991). A User’s Guide to Principal Components. New York: John Wiley & Sons.
Kaiser, H. F. (1970). “A Second Generation Little Jiffy.” Psychometrika 35:401–415.
Wickens, T. D. (1995). The Geometry of Multivariate Statistics. Hillsdale, NJ: Lawrence Erlbaum Associates.