Perhaps you should try some spelling variations:
cuu thuc » cuu tac
hat chau » ha chau, lai chau, hat nhan
hieu van » hieu va, thien van, lieu va
hai cau » hai chau, hai chu, hai hau
sach ly » sach y, sach lo, sach ty
su sach » so sach, vu sach
van cuu » van cau, van chu, van cu
nang ma » tang ma, sang ma, nang cao
ly nang » ky nang, ly hang, ly vang
va danh » va dinh, va hanh, dia danh
va dan » ca dan, va dao, va dau
ma hoi » mai hoi, xa hoi, ma hoa

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 ly nang ma hoi. hieu van cuu thuc ((va danh) OR (va dan)) ((hai cau) or (hat chau)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ly nang ma hoi. hieu van cuu thuc ((va danh) OR (va dan)) ((hai cau) OR (hat chau)) treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ly nang ma hoi. hieu van cuu thuc ((va danh) OR (va dan)) ((hai cau) or (hat chau)) treo".
• Adding a wildcard symbol may retrieve word variants: su sach ly nang ma hoi. hieu van cuu thuc ((va danh) OR (va dan)) ((hai cau) or (hat chau)) treo*.