What's happened to carpooling :
1980-1990 trends in North Carolina /
by David T. Hartgen and Kevin Bullard.

APA Citation

Bullard, K., Hartgen, D. T., University of North Carolina at Charlotte. Center for Interdisciplinary Transportation Studies. (1992). What's happened to carpooling: 1980-1990 trends in North Carolina. Charlotte, N.C.: Center for Interdisciplinary Transportation Studies, The University of North Carolina at Charlotte.

MLA Citation

Bullard, Kevin, David T Hartgen, and University of North Carolina at Charlotte. Center for Interdisciplinary Transportation Studies. What's Happened to Carpooling: 1980-1990 Trends In North Carolina. Charlotte, N.C.: Center for Interdisciplinary Transportation Studies, The University of North Carolina at Charlotte, 1992.