Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
vat dung » van dung, va dung, viet dung
dung doi » huong doi, dung tai, dung co
so sach » so sanh, bo sach, co sach
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
doi cua » dai cua, hoi cua
van am » van nam, van lam, van dam
cua tu » cua tuc, cua su, cua cu
thuc » thu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y ((nang ma) or (sang ma)) hoi. hieu van am thuc vat dung doi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y ((nang ma) OR (sang ma)) hoi. hieu van am thuc vat dung doi cua tu.
• Adding a wildcard symbol may retrieve word variants: so sach y ((nang ma) or (sang ma)) hoi. hieu van am thuc vat dung doi cua tu*.