Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
van thanh » ban thanh, van tuan
van hanh » ban hanh, van anh, van ban
may hoi » may thoi, tay hoi, mai hoi
van cac » van cau, van bac, dan cac
van hac » van hoc, van ha, van hai
y mang » cay mang
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 y mang may hoi. hieu ((van cac) or (van hac)) dat ((van hanh) OR (van thanh)) vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach y mang may hoi. hieu ((van cac) OR (van hac)) dat ((van hanh) OR (van thanh)) vi cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach y mang may hoi. hieu ((van cac) or (van hac)) dat ((van hanh) OR (van thanh)) vi cua vat".
• Adding a wildcard symbol may retrieve word variants: thuat sach y mang may hoi. hieu ((van cac) or (van hac)) dat ((van hanh) OR (van thanh)) vi cua vat*.