Perhaps you should try some spelling variations:
"canh gian va hoc viet nam" » "canh giac va hoc viet nam", "manh giang va hoc viet nam", "thanh gian va hoc viet nam", "canh gian van hoc viet nam", "canh gian ve hoc viet nam", "canh gian ha hoc viet nam"
"danh tac dai hoc viet nam" » "canh tac dai hoc viet nam", "danh bac dai hoc viet nam", "doanh tai dai hoc viet nam", "danh cac dai hoc viet nam", "danh tac da hoc viet nam"
"cong tac va hoc hien nam" » "cong ty va hoc hien nam", "cong tac va hoc phien nam", "cong tac va hoc hien nay", "cong tac va hoc vien nam", "cong tac van hoc hien nam", "cong tac da hoc hien nam", "cong tac xa hoc hien nam", "cong tuc va hoc hien nam"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("danh tac dai hoc viet nam") or ((("canh gian va hoc viet nam") or ("cong tac va hoc hien nam"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("danh tac dai hoc viet nam") OR ((("canh gian va hoc viet nam") OR ("cong tac va hoc hien nam"))))*.
• Removing quotes may allow a broader search: (( danh tac dai hoc viet nam ) or ((( canh gian va hoc viet nam ) or ( cong tac va hoc hien nam ))))*.