* {{cite book | last=Herring | first=George | title=America's Longest War : The United States and Vietnam, 1950-1975 with Poster | publisher=McGraw-Hill Humanities/Social Sciences/Languages | publication-place=Boston | date=2001-11-15 | isbn=0-07-253618-7}}
<ref name="e513">{{cite book | last=Herring | first=George | title=America's Longest War : The United States and Vietnam, 1950-1975 with Poster | publisher=McGraw-Hill Humanities/Social Sciences/Languages | publication-place=Boston | date=2001-11-15 | isbn=0-07-253618-7 | page=}}</ref>