Global Lightning Activity : A report on the current number of thunderstorms and the lightning strokes resulting from those thunderstorms throughout the world
Masters of Disaster, Lightning Glossary, The American National Red Cross (and Arizona State University), Washington, DC, USA 2007. http://www.azpbs.org/mastersofdisaster/pdf/Lightni ng/LightningGlossary.pdf, (Lghtng Sfty - Amer) {865}