Perhaps you should try some spelling variations:
thieu khang » chieu khong
thieu quang » hieu quang, thien quan, trien quang
nhung cong » dung cong, thong cong, hang cong
hanh tang » hanh trang, anh tang, hanh tung
hanh mang » nhanh mang, hanh trang, nhanh lang
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
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 khang) OR (thieu quang)) - ((hanh tang) or (hanh mang)) va nhung cong tac toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu khang) OR (thieu quang)) - ((hanh tang) OR (hanh mang)) va nhung cong tac toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu khang) OR (thieu quang)) - ((hanh tang) or (hanh mang)) va nhung cong tac toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu khang) OR (thieu quang)) - ((hanh tang) or (hanh mang)) va nhung cong tac toan cao*.