Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
thuc dan » thuc hanh, hoc dan, thuc vat
dan danh » van danh, han danh, ban danh
danh lai » danh sai, gianh lai, dinh lam
sach ly » sach lo, sach ty, sach hay
nang ma » tang ma, sang ma, nang cao
su viet » so viet
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) or (sach y)) nang ma hoi. hieu van nam thuc dan danh lai su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ly) OR (sach y)) nang ma hoi. hieu van nam thuc dan danh lai su viet.
• Adding a wildcard symbol may retrieve word variants: su ((sach ly) or (sach y)) nang ma hoi. hieu van nam thuc dan danh lai su viet*.