Freund, J. E., & Williams, F. J. a. (1964). Elementary business statistics: The modern approach. Prentice - hall.
Cita Chicago (17th ed.)Freund, John E., i Frank J.[et al] Williams. Elementary Business Statistics: The Modern Approach. New Jersey: Prentice - hall, 1964.
Cita MLA (9th ed.)Freund, John E., i Frank J.[et al] Williams. Elementary Business Statistics: The Modern Approach. Prentice - hall, 1964.
Atenció: Aquestes cites poden no estar 100% correctes.