Perhaps you should try some spelling variations:
khien bang » phien ban, khien dong
hanh trinh » canh tranh, hanh chinh
hien sang » hien trang, chieu sang, thien bang
hang cong » dang cong, hang nong, bang cong
trinh va » trinh van, trinh vat, trinh ve
dan toan » van toan, dan than, manh toan
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hien sang) or (khien bang)) - hanh trinh va ((hang cong) or (trong cong)) dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien sang) OR (khien bang)) - hanh trinh va ((hang cong) OR (trong cong)) dan toan cao.
• Adding a wildcard symbol may retrieve word variants: hoc ((hien sang) or (khien bang)) - hanh trinh va ((hang cong) or (trong cong)) dan toan cao*.