Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cau thuc » cau truc, cuu thuc, can thuc
hat chau » ha chau, lai chau, hat nhan
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
van cau » van dau, van hau, van chat
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
hai hau » hai chau, dai hau, hai hai
y nang » ky nang, ly nang, v nang
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: tu sach y nang ma hoi. hieu van cau thuc va hanh ((hai hau) or (hat chau)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ma hoi. hieu van cau thuc va hanh ((hai hau) OR (hat chau)) treo.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ma hoi. hieu van cau thuc va hanh ((hai hau) or (hat chau)) treo*.