Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hieu van » hieu va, thien van, lieu va
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
sach ky » sac ky, sach y, sach ty
vu sach » vu bach, su sach, vu khach
van cam » van nam, van lam, van cau
cam tu » cam thu, nam tu, dam tu
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi
ki su » ky 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: vu sach ky nang ((x hoi) OR (o hoi)). hieu van cam tu ((va hanh) OR (va danh)) ki su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang ((x hoi) OR (o hoi)). hieu van cam tu ((va hanh) or (va danh)) ki su triet~".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang ((x hoi) OR (o hoi)). hieu van cam tu ((va hanh) or (va danh)) ki su triet*.