The petroleum industry is the primary engine of the Libyan economy.

Yet for some, television revenue was the primary engine behind rises in overall earnings.

Agriculture was the primary engine of the kingdom from its beginnings in the 9th century.

Access to group rates is particularly important for small business owners, who are the primary engine of job creation in this country.

This became the primary engine of the line, eclipsing the 240.

"National governments must be the primary engine for increasing access to care," the report said.

It is trade, however, that is the primary engine for economic development.

A spacecraft could carry a mass driver as its primary engine.

Indeed, their increase in value has been the primary engine of the bull market.

Exports constitute the primary engine for Ireland's strong economic growth.