APA (7th ed.) Citation

Porter, D. R. (1988). Flexible zoning: How it works. Urban Land Institute.

Chicago Style (17th ed.) Citation

Porter, Douglas R. Flexible Zoning: How It Works. Washington: Urban Land Institute, 1988.

MLA (9th ed.) Citation

Porter, Douglas R. Flexible Zoning: How It Works. Urban Land Institute, 1988.