Perhaps you should try some spelling variations:
"arrest and assassination of ngo dinh dieu" » "arrest and assassination of ngo dinh dien", "arrest and assassination of ngo dinh tieu", "arrest and assassination of ngo vinh dieu", "arrest and assassination of nghi dinh dieu", "arrest and assassination of ngoc minh dieu", "arrest and assassination of nam dinh dieu"
"arrest and assassinations of ngo dinh dieu" » "arrest and assassinations of ngo dinh dien", "arrest and assassinations of ngo dinh tieu", "arrest and assassinations of ngo vinh dieu", "arrest and assassinations of nghi dinh dieu", "arrest and assassinations of ngoc minh dieu", "arrest and assassinations of nam dinh dieu"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("arrest and assassination of ngo dinh dieu") or ("arrest and assassinations of ngo dinh dieu"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("arrest and assassination of ngo dinh dieu") OR ("arrest and assassinations of ngo dinh dieu")).
• Removing quotes may allow a broader search: (( arrest and assassination of ngo dinh dieu ) or ( arrest and assassinations of ngo dinh dieu )).
• Adding a wildcard symbol may retrieve word variants: (("arrest and assassination of ngo dinh dieu") or ("arrest and assassinations of ngo dinh dieu"))*.