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
cua nhung » va nhung
hanh ban » thanh ban, hang ban, hanh san
huy toan » huy tran, huu toan, huy hoang
tap toan » tap doan, tap quan, bai toan
ban cua » ban quan
ty toan » ly toan, tam toan, ty doanh

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 ban cua nhung cong ((((ty toan) or (huy toan))) or (tap toan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sang - hanh ban cua nhung cong ((((ty toan) OR (huy toan))) OR (tap toan)) cao.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - hanh ban cua nhung cong ((((ty toan) or (huy toan))) or (tap toan)) cao*.