Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, diep quang
hanh trinh » canh tranh, hanh chinh
va duong » van duong, va tuong, va huong
vat dung » van dung, va dung, viet dung
cong van » cong vang, cong san, song van
van toan » van tuan, van tan, van thanh
toan cau » 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 ((hieu quang) or (hieu qua)) - hanh trinh ((va duong) or (vat dung)) cong van toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu quang) OR (hieu qua)) - hanh trinh ((va duong) OR (vat dung)) cong van toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu quang) or (hieu qua)) - hanh trinh ((va duong) or (vat dung)) cong van toan cau*.