Footnotes
- Miller , J. Robert . June 1963 . Central Iowa Farm Radio Study. , June , Cedar Rapids, Iowa : W. D. Lyon Company .
- Freund , John E. and Williams , Frank J. 1958 . Modem Business Statistics. , 257 – 260 . Engle‐wood Cliffs, N.J. : Prentice‐Hall, Inc. .