Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
hoc thieu » toc thieu, hoc hien
trinh ve » trinh he, trinh va, trinh viet
trinh vi » trinh va, trinh viet, trinh van
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
toan tap » toan ban

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 sach - hanh ((trinh ve) OR (trinh vi)) thong ((cong dan) or (cong san)) toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sach - hanh ((trinh ve) OR (trinh vi)) thong ((cong dan) OR (cong san)) toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sach - hanh ((trinh ve) OR (trinh vi)) thong ((cong dan) or (cong san)) toan tap".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - hanh ((trinh ve) OR (trinh vi)) thong ((cong dan) or (cong san)) toan tap*.