Perhaps you should try some spelling variations:
thai tren » thai tran, thi tren, thai trang
cam quoc » cac quoc, cao quoc, nam quoc
chau tho » chat thom, cau thi, phu tho
hang lai » hang tai, hang hai, hang loi
ban hang » ngan hang
quoc ban » quoc bao, quoc lan, quoc quan
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
y nang » ky nang, ly nang, v nang
ve cam » ve cham, ve cac, va cam
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: su sach y nang ((x hoi) OR (o hoi)). hieu ve cam quoc ban hang lai ((chau tho) or (thai tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang ((x hoi) OR (o hoi)). hieu ve cam quoc ban hang lai ((chau tho) OR (thai tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang ((x hoi) OR (o hoi)). hieu ve cam quoc ban hang lai ((chau tho) or (thai tren))".
• Adding a wildcard symbol may retrieve word variants: su sach y nang ((x hoi) OR (o hoi)). hieu ve cam quoc ban hang lai ((chau tho) or (thai tren))*.