Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hieu van » thien van, lieu va, hieu ve
nam thuc » nam thuoc, am thuc, nam thu
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
x hoi » xa hoi, o hoi, x ho

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 nang x hoi. ((hieu va) or (hieu van)) nam thuc va hanh va ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky nang x hoi. ((hieu va) OR (hieu van)) nam thuc va hanh va ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ky nang x hoi. ((hieu va) or (hieu van)) nam thuc va hanh va ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky nang x hoi. ((hieu va) or (hieu van)) nam thuc va hanh va ((cua tre) OR (cuu tre))*.