Perhaps you should try some spelling variations:
chieu tach » chiet tach, chieu sach, chiu trach
dung cong » dung trong
ho chieu » theo chieu, hoc thieu, doi chieu
trinh ve » trinh he, trinh vi, trinh viet
trinh va » trinh van, trinh vat, trinh vi
cong van » cong vang, cong san, song van
tai tap » bai tap, hai tap, lai tap
tai tao » tai sao

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 tach - hanh ((trinh ve) or (trinh va)) dung cong van ((tai tap) OR (tai tao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho chieu tach - hanh ((trinh ve) OR (trinh va)) dung cong van ((tai tap) OR (tai tao)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho chieu tach - hanh ((trinh ve) or (trinh va)) dung cong van ((tai tap) OR (tai tao))".
• Adding a wildcard symbol may retrieve word variants: ho chieu tach - hanh ((trinh ve) or (trinh va)) dung cong van ((tai tap) OR (tai tao))*.