References
- Dawson , Percy M. 1935 . The Physiology of Physical Education , 509 Baltimore : Williams and Wilkins Company .
- Levy , Robert L. , Mathers , James A.L. , Mueller , Alex A. and Nickerson , John L. October 18, 1947 . “Effect of Smoking Cigarettes on the Heart,” . J.A.M.A. , 135 : 417 – 422 .
- Personal communication to the authors.
- Steinhaus , Arthur H. and Grunderman , Florence M. 1941 . Tobacco and Health , 24 New York : Association Press .
- Willgoose , Carl E. 1947 . “Tobacco Smoking, Strength, and Muscular Endurance,” . Research Quarterly , 18 October : 219 – 225 .