Perhaps you should try some spelling variations:
ban hanh » ban hang
van hanh » van thanh, van anh, van ban
nam thuc » nam thuoc, am thuc, nam thu
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
ca viet » va viet, co viet, hoa viet
hieu ve » hieu va, hieu van
ky dang » ky nang, ky danh
me hoi » le hoi
ve nam » he nam, va nam, le nam
va ca » va cac, va cao, va cai

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky dang ((me hoi) or (ma hoa)). hieu ve nam thuc ((van hanh) OR (ban hanh)) va ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky dang ((me hoi) OR (ma hoa)). hieu ve nam thuc ((van hanh) OR (ban hanh)) va ca viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky dang ((me hoi) or (ma hoa)). hieu ve nam thuc ((van hanh) OR (ban hanh)) va ca viet".
• Adding a wildcard symbol may retrieve word variants: vu sach ky dang ((me hoi) or (ma hoa)). hieu ve nam thuc ((van hanh) OR (ban hanh)) va ca viet*.