Perhaps you should try some spelling variations:
sach thue » sach thu, sach thieu, sach tham
cua viet » ca viet, hoa viet, cua vat
hanh dai » hanh tai, hanh dao, vanh dai
van hanh » van thanh, ban hanh, van anh
hieu va » lieu va, hieu qua
duc van » duc va, duc tan, duc manh
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
hieu ve » hieu van

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ty) or (sach thue)) nang xa hoi. ((hieu ve) or (hieu va)) pham duc van hanh dai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach thue)) nang xa hoi. ((hieu ve) OR (hieu va)) pham duc van hanh dai cua viet.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach thue)) nang xa hoi. ((hieu ve) or (hieu va)) pham duc van hanh dai cua viet*.