Perhaps you should try some spelling variations:
thieu sang » chieu sang, thieu khang, thieu quang
nhung cong » thong cong, hang cong, nhung don
hoc thieu » toc thieu, hoc hien
trinh vat » trinh van, trinh luat, sinh vat
dung cong » dung trong
trinh va » trinh van, trinh ve, trinh vi
sac thai » rac thai, sach tham, toc thai
thai cao » tai cao, thoai cac, thuat cao

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sang - hanh ((trinh va) OR (trinh vat)) ((nhung cong) OR (dung cong)) sac thai cao~.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - hanh ((trinh va) or (trinh vat)) ((nhung cong) or (dung cong)) sac thai cao*.