Littlejohn, Margaret, and National Park Service. Great Smoky Mountains National Park Visitor Studies: Summer and Fall 1996. University of Ohio, 1997.

Littlejohn, Margaret. Great Smoky Mountains National Park Visitor Study: Summer 1996. University of Idaho, 1997.

Littlejohn, Margaret. Great Smoky Mountains National Park Visitor Study: Summer and Fall 1996. University of Idaho, 1997.