A citation should be referenced when using the GCMD controlled keywords in scientific literature, websites, software tools, etc. Please cite the keyword as: Global Change Master Directory (GCMD). 2015. GCMD Keywords, Version 8.1. Greenbelt, MD: Global Change Data Center, Science and Exploration Directorate, Goddard Space Flight Center (GSFC) National Aeronautics and Space Administration (NASA). URL:http://gcmd.nasa.gov/learn/keywords.html |