He also had an invaluable source of gossip in the priests.

We need a new approach to energy development that makes better use of these invaluable sources.

They provided an invaluable source of bedside aid in the war effort.

The work remains an invaluable source of information on trees and arboriculture.

He added: "The party elders are invaluable sources of advice to me."

This book has since become an invaluable source in understanding the beliefs of these groups.

The internet is an invaluable source of information about computer hardware.

Blow became a close friend and an invaluable source of inspiration.

Those who decided to make careers with the police would become an invaluable source of management talent.

Sarmiento's work is considered an invaluable source of information for that period.