Gentlemen
Salaam Aleykum

A good overall look at the campaign is in:
Oman's Insurgencies - The Sultanate's Struggle for Supremacy by J.E. Peterson.

Books on the role of the Omani and Baluch infantry, who did most of the legwork, are:
Muscat Command by Peter Thwaites.

Dangerous Frontiers by Brian Ray

Where Soldiers Fear to Tread by Ranulph Fiennes

An interesting command perspective can be read in:
List The Bugle - Reminiscences of an Irish Soldier by Corran Purdon

The experiences of an Air Despatcher are written in:
The Secret War - Dhofar 1971/1972 by David C. Arkless.

(Amber39 was my callsign for a time during the campaign.)