When they returned to the university, the four students called on others to join them the next day at Woolworth's.

VOA: special.2010.01.29

Alternate bearing is when a tree produces a heavy crop one year, called an "on-crop,"

VOA: special.2009.11.10

When he and his son, Bobby Bare,Junior, decided to make this album, they called on everyone they knew in the business who was a fan of Shel Silverstein.

VOA: special.2010.06.04

Main said the government is now willing to go directly to court to shut down mines when necessary, and he called on Congress to enact tougher enforcement measures.

VOA: standard.2010.04.27

"I embarked on the road of sustainability or ethics or biodiversity about five years ago, when I founded a company called Noir I work with 16,000 farmers in Africa.

VOA: standard.2010.01.31