Perhaps you should try some spelling variations:
cuu thuc » cuu tac
hai chau » lai chau, ha chau, hat chau
hieu van » hieu va, thien van, lieu va
hai cau » hai chu, hai hau, hoi cau
va danh » va dinh, va dan, va hanh
thuc va » thuc vat, thuc dan, thuc day
su sach » so sach, vu sach
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
van cuu » van cau, van chu, van cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y ((nang ma) or (tang ma)) hoi. hieu van cuu thuc va danh ((hai cau) or (hai chau)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((nang ma) OR (tang ma)) hoi. hieu van cuu thuc va danh ((hai cau) OR (hai chau)) treo.
• Adding a wildcard symbol may retrieve word variants: su sach y ((nang ma) or (tang ma)) hoi. hieu van cuu thuc va danh ((hai cau) or (hai chau)) treo*.