Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
van hanh » van thanh, ban hanh, van anh
va danh » va dinh, va dan, va hanh
su sach » so sach, vu sach
hieu va » hieu qua
nang ma » tang ma, sang ma, nang cao
sach v » sach va, sach y, sach 2
ma hoi » mai hoi, xa hoi, ma hoa
v nang » va nang, vu nang, van nang
vi su » va su, ve su, ki su

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. ((hieu va) OR (lieu va)) tai trung ((van hanh) OR (va danh)) vi su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach v nang ma hoi. ((hieu va) OR (lieu va)) tai trung ((van hanh) or (va danh)) vi su triet~".
• Adding a wildcard symbol may retrieve word variants: su sach v nang ma hoi. ((hieu va) OR (lieu va)) tai trung ((van hanh) or (va danh)) vi su triet*.