Essential Functions 5 : Functions required to be performed by statute, Executive Order, or otherwise deemed essential by the heads of principal organizational elements to meet mission requirements
The Institute for Crisis, Disaster, and Risk Management (ICDRM) at the George Washington University (GWU), Emergency Management Glossary of Terms, Washington, D.C., USA 2007. http://www.gwu.edu/~icdrm/publications/PDF/GLOSSAR Y%2002-19-2007.pdf, (Emr Mgt/ Crisis, Dzstr and Rsk - Amer) {478}
