'Tiger in the Barb Wire' by Howard Simpson...

I am currently re-reading this book that I first discovered in the mid '90s. It is an excellent first person account on the scene account of the transition of French to American eras in Vietnam. I only saw parts of the movie Dien Bien Phu and can't remember if the Howard Simpson character played by Donald Pleasance is depicted at DBP during the battle. As per the book, Simpson was at DBP before the battle to survey the scene but not there during the battle.

I can't find Dien Bien Phu on Netflix or on Amazon. Does anyone know where I can buy a copy of this movie?