Smith, Thomas J., and David Kriebel. "Irreversible Discrete Disease Processes: Silica and Lung Cancer." A Biologic Approach to Environmental Assessment and Epidemiology. : Oxford University Press, 2010-08-01. Oxford Scholarship Online. 2011-01-01. Date Accessed 20 May. 2013 <http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195141566.001.0001/acprof-9780195141566-chapter-015>.
Smith, T., & Kriebel, D.(2010-08-01). Irreversible Discrete Disease Processes: Silica and Lung Cancer. In A Biologic Approach to Environmental Assessment and Epidemiology. : Oxford University Press. Retrieved 20 May. 2013, from http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195141566.001.0001/acprof-9780195141566-chapter-015.
Smith, Thomas J., and David Kriebel. "Irreversible Discrete Disease Processes: Silica and Lung Cancer." In A Biologic Approach to Environmental Assessment and Epidemiology. : Oxford University Press, 2010-08-01. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195141566.001.0001/acprof-9780195141566-chapter-015.
Smith TJ, Kriebel D. Irreversible Discrete Disease Processes: Silica and Lung Cancer. In: Smith TJ, Kriebel D. A Biologic Approach to Environmental Assessment and Epidemiology. Oxford University Press; 2010. http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195141566.001.0001/acprof-9780195141566-chapter-015. Accessed May 20, 2013.