If you're interested in fiction for that era, you might try (if you haven't already):
Platoon Leader
by James R. McDonough
This book is the story of one young lieutenants growth during the year he fought in Vietnam. It is the story of the hard choices that a leader will have to face in combat. The author’s main thesis is that war is a constant struggle between responsibilities of a leader and the desire to abandon your sense of humanity when faces with the gruesome reality of war. This book is a must for any professional soldier’s reading list. The lessons that can be derived are as appropriate for the professional NCO as for the professional officer.
Biography & Autobiography - Military; History - Military - Vietnam | Presidio Press | Trade Paperback | June 1996 | $13.95 | 0-89141-606-4
Author Biography
Cololonel James McDonough, USA (Ret.), graduated from West Point and served in Vietnam as an infantry platoon leader in the legendary 173d Airborne Brigade. A military theorist who has helped shape the post-Cold War army’s thinking, he is also the author of The Defense of Hill 781 and The Limits of Glory. Now retired from active duty, McDonough lives with his family in Tallahassee, Florida.
P.S. Sorry about all the "cut & paste". It's just that they explained it better than my motivation towards typing would allow me to.