They show us our forefathers and are an invaluable aid to the social history of our country.

The construction of this road was an invaluable aid in the development of the county.

He has been an invaluable aid in maintaining the verisimilitude of the original battle.

He could not have mounted this Khurabian mission half as quickly without her invaluable aid.

That is why it is such an invaluable aid in getting lost.

It's an invaluable aid when it comes to winning arguments.

An investigator's report could be an invaluable aid, telling them where she went and when, whom she saw.

A magician such as yourself could provide me invaluable aid.

"He is an aid most invaluable in the assistance of expectant mothers."

Once acquired it is an invaluable aid to genuine understanding and sensitive response.