Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hanh dien » nhanh dien, hang dien, danh dien
dien cuu » dien cuc, dien cu, dien cua
dau thuc » dan thuc, dai thuc, dam thuc
hieu van » thien van, lieu va, hieu ve
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
cuu tre » cua tre, cau tren, cau treo
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
mang xa » mang may, dang xay, mang cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ky ((mang xa) or (lang xa)) hoi. ((hieu van) OR (hieu va)) dau thuc va hanh dien cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky ((mang xa) OR (lang xa)) hoi. ((hieu van) OR (hieu va)) dau thuc va hanh dien cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ky ((mang xa) or (lang xa)) hoi. ((hieu van) OR (hieu va)) dau thuc va hanh dien cuu tre".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky ((mang xa) or (lang xa)) hoi. ((hieu van) OR (hieu va)) dau thuc va hanh dien cuu tre*.