Perhaps you should try some spelling variations:
hoc chieu » hoc thieu, hoc hien, hoc dieu
dung cong » dung trong
ho chieu » theo chieu, hoc thieu, doi chieu
tranh su » trang su, tranh cua, trang suc
trinh su » trinh tu, trinh san, trinh cau
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 chieu) or (ho chieu)) xanh - canh ((tranh su) OR (trinh su)) dung cong tac toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc chieu) OR (ho chieu)) xanh - canh ((tranh su) OR (trinh su)) dung cong tac toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc chieu) or (ho chieu)) xanh - canh ((tranh su) OR (trinh su)) dung cong tac toan cao".
• Adding a wildcard symbol may retrieve word variants: ((hoc chieu) or (ho chieu)) xanh - canh ((tranh su) OR (trinh su)) dung cong tac toan cao*.