Perhaps you should try some spelling variations:
lieu tinh » trieu tinh, diep tinh
bien tinh » bi tinh, yen tinh, diep tinh
hanh tran » hanh trang, thanh tran, hanh tram
van bang » van nang, von bang, van hang
cong van » cong vang, cong san, song van
van tuan » van quan, anh tuan
tuan cao » toan cao, juan cao, quang cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((lieu tinh) or (bien tinh)) - hanh tran ((van bang) or (van ban)) cong van tuan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((lieu tinh) OR (bien tinh)) - hanh tran ((van bang) OR (van ban)) cong van tuan cao.
• Adding a wildcard symbol may retrieve word variants: hoc ((lieu tinh) or (bien tinh)) - hanh tran ((van bang) or (van ban)) cong van tuan cao*.