Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
cua tre » cua te, cuu tre, cua triet
xanh di » danh di, vanh dai, xanh tai
va xanh » va danh, va hanh, va anh
hieu ve » hieu va, hieu van
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
ve cac » va cac, vien cac
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky nang ((x hoi) or (o hoi)). hieu ve cac nuoc va xanh di ((cua tre) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky nang ((x hoi) OR (o hoi)). hieu ve cac nuoc va xanh di ((cua tre) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: te sac ky nang ((x hoi) or (o hoi)). hieu ve cac nuoc va xanh di ((cua tre) or (su triet))*.