Perhaps you should try some spelling variations:
cac truc » cau truc, cac tru, cac trung
truc van » truc va, thuc van, truc ban
van hanh » van thanh, ban hanh, van anh
hanh hai » thanh hai, nhanh hai, hang hai
su triet » su viet, su tien, ve triet
su sach » so sach, vu sach
qua cac » cua cac
y nang » ky nang, ly nang, v nang
hai su » hai vu, lai su, hai so
o hoi » co hoi, o hoc, o hoa
o hai » co hai, so hai, o lai

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang ((o hoi) or (o hai)). hieu qua cac truc van hanh hai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang ((o hoi) OR (o hai)). hieu qua cac truc van hanh hai su triet.
• Adding a wildcard symbol may retrieve word variants: su sach y nang ((o hoi) or (o hai)). hieu qua cac truc van hanh hai su triet*.