Perhaps you should try some spelling variations:
chieu tinh » trieu tinh, lieu tinh, chau tinh
chinh tai » chinh tri
dung cong » dung trong
ho chieu » theo chieu, hoc thieu, doi chieu
chinh va » chinh ta, hanh va, tinh va
tac toan » tap toan, tam toan, hach toan
toan cau » 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: ho chieu tinh - hanh ((chinh va) OR (chinh tai)) ((dung cong) or (dang cong)) tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho chieu tinh - hanh ((chinh va) OR (chinh tai)) ((dung cong) OR (dang cong)) tac toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho chieu tinh - hanh ((chinh va) OR (chinh tai)) ((dung cong) or (dang cong)) tac toan cau".
• Adding a wildcard symbol may retrieve word variants: ho chieu tinh - hanh ((chinh va) OR (chinh tai)) ((dung cong) or (dang cong)) tac toan cau*.