Perhaps you should try some spelling variations:
theo chieu » theo tieu, ho chieu, theo chu
hoc thieu » toc thieu, hoc hien
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
nang cong » nang song, dang cong, bang cong
tac toan » tam toan, hach toan, tich toan
tap toan » tap doan, tap quan, bai toan
tinh va » tich va, trinh van, trinh vat
va nang » van nang, da nang, cam nang

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) or (theo chieu)) xanh - hanh tinh va nang cong ((tac toan) OR (tap toan)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc thieu) OR (theo chieu)) xanh - hanh tinh va nang cong ((tac toan) OR (tap toan)) ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc thieu) or (theo chieu)) xanh - hanh tinh va nang cong ((tac toan) OR (tap toan)) ban".
• Adding a wildcard symbol may retrieve word variants: ((hoc thieu) or (theo chieu)) xanh - hanh tinh va nang cong ((tac toan) OR (tap toan)) ban*.