Ashford, J. R. (1977). Statistics for management. Institute of Personnel Management.
Cita Chicago (17th ed.)Ashford, J. R. Statistics for Management. London: Institute of Personnel Management, 1977.
Cita MLA (8th ed.)Ashford, J. R. Statistics for Management. Institute of Personnel Management, 1977.
Atenció: Aquestes cites poden no estar 100% correctes.