Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
hoc thieu » toc thieu, hoc hien
cong san » cong tac
va hang » van hang, va lang, va hanh
va nang » van nang, da nang, cam nang
than ma » than man, khan ma, nhan ma
than va » thanh va, nhan va, toan va

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 - nhanh quang ((va hang) OR (va nang)) cong san ((than ma) or (than va))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sach - nhanh quang ((va hang) OR (va nang)) cong san ((than ma) OR (than va)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sach - nhanh quang ((va hang) OR (va nang)) cong san ((than ma) or (than va))".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - nhanh quang ((va hang) OR (va nang)) cong san ((than ma) or (than va))*.