Perhaps you should try some spelling variations:
thieu sang » chieu sang, thieu khang, thieu quang
hanh trinh » canh tranh, hanh chinh
hoc thieu » toc thieu, hoc hien
trong tac » trong cac, tuong tac, trong tan
van dung » van dong, xay dung, tin dung
tac vang » cac van, tac dung, tac dong
vang ban » van ban, hang ban, nang ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thieu sang - hanh trinh ((van dung) or (viet trung)) trong tac vang ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sang - hanh trinh ((van dung) OR (viet trung)) trong tac vang ban*.