Perhaps you should try some spelling variations:
doan thien » hoan thien, doan thi, toan thiet
hanh trinh » canh tranh, hanh chinh
ton thien » hoan thien, toan thiet, tran thien
dung cong » dung trong
trinh va » trinh van, trinh vat, trinh ve
cong san » cong tac
toan cao » toan ban
toan tap » toan ban
va dung » van dung, va duong, vat dung

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((ton thien) or (doan thien)) manh - hanh trinh va dung cong san ((toan cao) or (toan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ton thien) OR (doan thien)) manh - hanh trinh va dung cong san ((toan cao) OR (toan tap)).
• Adding a wildcard symbol may retrieve word variants: ((ton thien) or (doan thien)) manh - hanh trinh va dung cong san ((toan cao) or (toan tap))*.