From BiblePortal Wikipedia

Hastings' Dictionary of the Bible [1]

Hazar-Addar . A place on the southern border of Canaan, west of Kadesh-barnea (  Numbers 34:4 ). It appears to be the same as Hezron of   Joshua 15:3 , which in the latter passage is connected with but separated from Addar .

Holman Bible Dictionary [2]

 Numbers 34:4AddarKadesh

Fausset's Bible Dictionary [3]

Between Kadesh Barnea and Azmon ( Numbers 34:4). A landmark on the southern boundary of the Promised Land.

Easton's Bible Dictionary [4]

 Numbers 34:4 Joshua 15:3