Perhaps you should try some spelling variations:
tap trung » tap truong, tai trung, tao trung
cua viet » ca viet, hoa viet, cua vat
van hanh » van thanh, ban hanh, van anh
va danh » va dinh, va dan, va hanh
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
sach v » sach va, sach y, sach 2
ma hoi » mai hoi, ma hoa, me hoi
v nang » va nang, vu nang, van nang
vi cua » vai cua, di cua
va tap » va tac

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach v nang ((ma hoi) OR (xa hoi)). hieu va tap trung ((van hanh) OR (va danh)) vi cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach v nang ((ma hoi) OR (xa hoi)). hieu va tap trung ((van hanh) or (va danh)) vi cua viet~".
• Adding a wildcard symbol may retrieve word variants: su sach v nang ((ma hoi) OR (xa hoi)). hieu va tap trung ((van hanh) or (va danh)) vi cua viet*.