Perhaps you should try some spelling variations:
thieu tinh » trieu tinh, chieu tinh, thien tinh
hoc thieu » toc thieu, hoc hien
tranh cua » doanh cua, manh cua
ban nong » ban nang, ban tong, ban huong
ban cong » bang cong, van cong, phan cong
tap toan » tap doan, bai toan
tap quan » tac quan, hai quan

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 tinh - canh tranh cua ((ban nong) OR (ban cong)) ((tap toan) OR (tap quan)) tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu tinh - canh tranh cua ((ban nong) or (ban cong)) ((tap toan) OR (tap quan)) tap~".
• Adding a wildcard symbol may retrieve word variants: hoc thieu tinh - canh tranh cua ((ban nong) or (ban cong)) ((tap toan) OR (tap quan)) tap*.