Nitrate nitrogen in Iowa rivers :
long-term trends /
[prepared by Iowa Department of Natural Resources, Geological Survey Bureau ; photos by Gary Hightshoe].

APA Citation

Hightshoe, G. L., Iowa. Department of Natural Resources. Geological Survey Bureau. (2001). Nitrate nitrogen in Iowa rivers: long-term trends. [Iowa City, Iowa: Iowa Department of Natural Resources, Geological Survey Bureau.

MLA Citation

Hightshoe, Gary L, and Iowa. Department of Natural Resources. Geological Survey Bureau. Nitrate Nitrogen In Iowa Rivers: Long-term Trends. [Iowa City, Iowa: Iowa Department of Natural Resources, Geological Survey Bureau, 2001.

Warning: These citations may not always be complete (especially for serials).