Aurora Borealis, 1999. [online] http://virtual.finland.fi/finfo/english/aurora_borealis.html
Natural Wonders, 1995,1999,2004. [online] http://ce.eng.usf.edu/pharos/wonders/natural/
Northern Lights, 2003. [online] http://www.northernlight.com/
Photographs of Grand Canyon courtesy of Mary's Grandparents.
Surviving the Seven Natural Wonders of the World, 2004. [online] http://library.thinkquest.org/CR0215502/home.html
The Natural Wonders of the World, 1994-2000. [online] http://www.kaibab.org/misc/gc_7wond.htm
The Natural Wonders of the World, 2000, [online] http://www.field-trips.org/tours/sci/natwon/_tourlaunch1.htm
The Seven Natural Wonders of the World, 1997. [online] http://www.kaibab.org/misc/gc_7wond.htm
The Seven Natural Wonders, 1999. [online] http://library.thinkquest.org/J002388/naturalwonders.html