Perhaps you should try some spelling variations:
thieu hach » thien hach, chieu sach, hieu cach
hoc thieu » toc thieu, hoc hien
hanh hang » thanh hang, hang hang, hanh han
cong dan » cong san, cong tan, huong dan
toan cao » toan ban
toan tap » toan ban
va dang » van dang, va lang, da dang
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 hach - hanh hang ((va dang) OR (va nang)) cong dan ((toan cao) or (toan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu hach - hanh hang ((va dang) OR (va nang)) cong dan ((toan cao) OR (toan tap)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu hach - hanh hang ((va dang) OR (va nang)) cong dan ((toan cao) or (toan tap))".
• Adding a wildcard symbol may retrieve word variants: hoc thieu hach - hanh hang ((va dang) OR (va nang)) cong dan ((toan cao) or (toan tap))*.