Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
sach ky » sac ky, sach y, sach ty
van cac » van hac, van cau, van bac
cac dat » cac dan, cai dat, cac dai
ma hoi » mai hoi, xa hoi, me hoi
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ky nang ((ma hoi) or (ma hoa)). hieu van cac dat ((van hanh) OR (ban hanh)) vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky nang ((ma hoi) OR (ma hoa)). hieu van cac dat ((van hanh) OR (ban hanh)) vi cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ky nang ((ma hoi) or (ma hoa)). hieu van cac dat ((van hanh) OR (ban hanh)) vi cua vat".
• Adding a wildcard symbol may retrieve word variants: thuat sach ky nang ((ma hoi) or (ma hoa)). hieu van cac dat ((van hanh) OR (ban hanh)) vi cua vat*.