Perhaps you should try some spelling variations:
dang xay » dang van, van xay
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
sach ky » sac ky, sach ty, sach kem
xay hoi » xa hoi, tay hoi, cay phoi
thuc va » thuc vat, thuc dan, thuc day
va dinh » van dinh, va kinh, va tinh
dinh le » dinh ve, dinh ly, dinh ket
cau tre » cau tren, cau treo, cau tra
le cau » ke cau, le mau, le cap

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ky) or (sach y)) dang xay hoi. hieu van nam thuc va dinh le cau tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sach y)) dang xay hoi. hieu van nam thuc va dinh le cau tre.
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) or (sach y)) dang xay hoi. hieu van nam thuc va dinh le cau tre*.