SPIEGEL MURRAY R [A], S. L. J. [. (1999). SCHAUM`S OUTLINE OF THEORY AND PROBLEMS OF STATISTICS - 3RD ED (3.). TATA MCGRAW-HILL PUBLISHING COMPANY LIMITED.

SPIEGEL MURRAY R [A], STEPHENS LARRY J [A]. SCHAUM`S OUTLINE OF THEORY AND PROBLEMS OF STATISTICS - 3RD ED. 3. NEW DELHI: TATA MCGRAW-HILL PUBLISHING COMPANY LIMITED, 1999.

SPIEGEL MURRAY R [A], STEPHENS LARRY J [A]. SCHAUM`S OUTLINE OF THEORY AND PROBLEMS OF STATISTICS - 3RD ED. 3. TATA MCGRAW-HILL PUBLISHING COMPANY LIMITED, 1999.