Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
thieu sang » chieu sang, thieu khang, thieu quang
hoc thieu » toc thieu, hoc hien
trinh han » trinh quan
tinh cua » trinh cua, sinh cua, tinh chat
cong san » cong tac
san toan » van toan, dan toan, manh toan
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 thieu sang - hanh ((tinh cua) or (trinh han)) nhung cong san toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sang - hanh ((tinh cua) OR (trinh han)) nhung cong san toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - hanh ((tinh cua) or (trinh han)) nhung cong san toan cau*.