Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
cau thuc » cau truc, cuu thuc, can thuc
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
van cau » van dau, van hau, van chat
va danh » va dinh, va dan, dia danh
cao hoi » cau hoi, co hoi, cao hoc
cuu tre » cua tre, cau tren, cau treo
va hanh » van hanh, va thanh, ban hanh
y nang » ky nang, ly nang, v nang

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