Walpole, R. E. (1976). Elementary statistical concepts. Macmillan.
Cita Chicago (17th ed.)Walpole, Ronald E. Elementary Statistical Concepts. Macmillan, 1976.
Cita MLA (9th ed.)Walpole, Ronald E. Elementary Statistical Concepts. Macmillan, 1976.
Atenció: Aquestes cites poden no estar 100% correctes.