Happy Birthday to the Richter Scale inventor: It's National Richter Scale Day - CBS Los Angeles

The Richter Scale measures quakes in a range from 0 to 9. On the scale, each increase in number represents an earthquake 10 times more powerful.

Boxoffice-November.06.1978

Richter Scale Day – Fun Holiday

History Archive - STORIES: The Foundation for the AIDS Monument

2007-2008 Peru State Times (Peru, NE) - issues 1-10 by Peru State

NATIONAL RICHTER SCALE DAY: National Richter Scale Day on April 26

Boxoffice-November.06.1954

It's National Richter Day! On this day in 1900 Charles Richter

Germany Is Celebrating Gerhard Richter's 90th Birthday With a

Timeline of United States inventions (1890–1945) - Wikipedia

63rd Annual GRAMMY AWARDS® Program Book by AFMLA - Issuu

Boxoffice-November.28.1977

2007-2008 Peru State Times (Peru, NE) - issues 1-10 by Peru State