Perhaps you should try some spelling variations:
thien van » thi van
hieu van » hieu va, lieu va, hieu ve
vat danh » va danh, van danh, luat danh
nam thuc » nam thuoc, am thuc, nam thu
sach ly » sach y, sach lo, sach ty
nang ma » tang ma, sang ma, nang cao
ly nang » ky nang, ly hang, ly vang
hai cau » hai chau, hai chu, hoi cau
hai hau » hai chau, dai hau, hai hai
so sach » so sanh, bo sach, co sach
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: so sach ly nang ma hoi. ((hieu van) or (thien van)) nam thuc vat danh ((hai cau) OR (hai hau)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ly nang ma hoi. ((hieu van) OR (thien van)) nam thuc vat danh ((hai cau) OR (hai hau)) treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ly nang ma hoi. ((hieu van) or (thien van)) nam thuc vat danh ((hai cau) OR (hai hau)) treo".
• Adding a wildcard symbol may retrieve word variants: so sach ly nang ma hoi. ((hieu van) or (thien van)) nam thuc vat danh ((hai cau) OR (hai hau)) treo*.