Perhaps you should try some spelling variations:
thieu tach » thien hach, chiet tach, chieu sach
hoc thieu » toc thieu, hoc hien
trinh van » trinh han, trinh quan, trinh toan
trinh va » trinh vat, trinh ve, trinh vi
song tan » song than, song van, song tam
cong tan » cong tac, cong san, cong thanh
van cau » van dau, van hau, van chat

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 tach - canh ((trinh va) OR (trinh van)) nhung ((song tan) OR (cong tan)) van cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu tach - canh ((trinh va) or (trinh van)) nhung ((song tan) OR (cong tan)) van cau~".
• Adding a wildcard symbol may retrieve word variants: hoc thieu tach - canh ((trinh va) or (trinh van)) nhung ((song tan) OR (cong tan)) van cau*.