She says one possibility is a decrease in the number of school nurses during the period they studied.

VOA: special.2009.08.06

The hot line had an important purpose: to prevent accidental war between the two competitors during the period known as the Cold War.

VOA: special.2009.12.06

Many magazines failed. The two big successes of the period were Life Magazine and the Reader's Digest.

VOA: special.2011.04.14

The area where the flutes were found has been linked to the Aurignacian culture within the period of history known as the Upper Paleolithic.

VOA: special.2009.08.18

Experts say they are very different from the works of other famous architects of the period.

VOA: special.2009.12.13

During the period of the Cold War, an estimated 30 million people in Eastern Europe and the Soviet Union listened to him on the radio.

VOA: special.2009.01.30

It takes place during Prohibition, the period when the United States banned alcohol.

VOA: special.2011.04.25

This was during the period known as the Harlem Renaissance.

VOA: special.2009.02.22

The period became known as the Great Depression.

VOA: special.2010.06.13

The period represented a rebirth of artistic development.

VOA: special.2010.02.03

It doesn't mean it's going to be easy. But,I think it can be over the period of time that we're talking about."

VOA: standard.2010.07.22

It will consider the period from summer 2001, before military operations began in March 2003, and our subsequent involvement in Iraq right until the end of July this year,".

VOA: standard.2009.06.15

He called the runoff and the period afterward when a new government is formed a "turning point" in the effort to defeat the extremists and deliver good government and economic development to Afghanistan.

VOA: standard.2009.10.23

"Historically it's one of the most important parts of the period of World War II in France,the roundup - the rafle du Vel dHiv - is a symbol of collaboration between the French police and the German occupying authorities."

VOA: standard.2010.04.10