APA

Hagstrom Robert G,, . (1999). The Warren Buffett portfolio : Mastering the power of the focus investment strategy. New York: John Wiley & Sons Inc.

Chicago

Hagstrom Robert G,, . 1999. The Warren Buffett portfolio : Mastering the power of the focus investment strategy. New York: John Wiley & Sons Inc.

Harvard

Hagstrom Robert G,, . (1999). The Warren Buffett portfolio : Mastering the power of the focus investment strategy. New York: John Wiley & Sons Inc.

MLA

Hagstrom Robert G,, . The Warren Buffett portfolio : Mastering the power of the focus investment strategy. New York: John Wiley & Sons Inc. 1999.