If you were working on a geography project, the source that would probably be of least to you is a(n) atlas gazetteer telephone directory

telephone directory

Explanation:

An atlas is a book that have a collection of maps.

A gazetteer is a geographical dictionary that has information like statistics, list of places, features of countries, regions.

A telephone directory is a book in which you can find contact information of people and businesses.

According to these definitions, if you were working on a geography project, the source that would probably be of least help to you is a telephone directory as it doesn't have any information related to geography.

answer; i thinking 4.5 million. in sydney australia;