APA
Hagstrom R. G., . (1999). The Warren Buffett portfolio : mastering the power of the focus investment strategy. New York, N.Y: Wiley.
Chicago
Hagstrom Robert G, . 1999. The Warren Buffett portfolio : mastering the power of the focus investment strategy. New York, N.Y: Wiley.
Harvard
Hagstrom R. G., . (1999). The Warren Buffett portfolio : mastering the power of the focus investment strategy. New York, N.Y: Wiley.
MLA
Hagstrom Robert G, . The Warren Buffett portfolio : mastering the power of the focus investment strategy. New York, N.Y: Wiley. 1999.