Perhaps you should try some spelling variations:
dang xay » dang van, van xay
hanh doi » thanh doi, hanh noi, hang doi
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
nam thuc » nam thuoc, am thuc, nam thu
so sach » so sanh, bo sach, co sach
hieu ly » hieu ky, lieu ly, dieu ly
doi cuu » doi cua, doi cuoc
cuu tre » cua tre, cau tren, cau treo
hieu le » hieu ve, hieu he, tieu le
sach v » sach va, sach y, sach 2

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 v ((dang xay) or (nang x)) hoi. ((hieu le) or (hieu ly)) nam thuc van hanh doi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach v ((dang xay) OR (nang x)) hoi. ((hieu le) OR (hieu ly)) nam thuc van hanh doi cuu tre.
• Adding a wildcard symbol may retrieve word variants: so sach v ((dang xay) or (nang x)) hoi. ((hieu le) or (hieu ly)) nam thuc van hanh doi cuu tre*.