J. H. Bates

Intensity of physical activity and risk of coronary heart disease.

B. Ainsworth, C. Macera, D. Jones, 2001, Journal of the American Medical Association (JAMA).

Total and leisure-time walking among U.S. adults should every step count?

B. Ainsworth, M. Serdula, C. Gillespie, 2005, American journal of preventive medicine.