Perhaps you should try some spelling variations:
"vu canh tranh tren" » "vu canh trinh tren", "vu canh tran tren", "vu canh tranh trong", "ve canh tranh tren", "vu anh tranh tren", "vu manh tranh tren"
"vu hoach dinh tren" » "vu hoang dinh tren", "vu hoach dinh trong", "vu hoach dinh tri", "vu hoach dinh dien", "quy hoach dinh tren", "thu hoach dinh tren", "qui hoach dinh tren"
"vu hoach tinh dien" » "vu hoa tinh dien", "vu hoat tinh dien", "vu hanh tinh dien", "quy hoach tinh dien", "thu hoach tinh dien", "qui hoach tinh dien", "vu hoach tinh bien", "vu hoach tinh vien", "vu hoach tinh tien"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("vu canh tranh tren") or ((("vu hoach dinh tren") or ("vu hoach tinh dien"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("vu canh tranh tren") OR ((("vu hoach dinh tren") OR ("vu hoach tinh dien")))).
• Removing quotes may allow a broader search: (( vu canh tranh tren ) or ((( vu hoach dinh tren ) or ( vu hoach tinh dien )))).
• Adding a wildcard symbol may retrieve word variants: (("vu canh tranh tren") or ((("vu hoach dinh tren") or ("vu hoach tinh dien"))))*.