Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
van hanh » van thanh, ban hanh, van anh
so sach » so sanh, bo sach, co sach
hieu ve » hieu va, hieu van
hanh oi » hanh noi, hanh moi, hanh voi
su sach » vu sach
ve cam » ve cham, ve cac, va cam
cam tu » cam thu, nam tu, dam tu
tu van » tu va
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai
oi su » ki su, vi su

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) or (so sach)) ky nang ((x hoi) OR (o hoi)). hieu ve cam tu van hanh oi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ky nang ((x hoi) OR (o hoi)). hieu ve cam tu van hanh oi su triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) ky nang ((x hoi) OR (o hoi)). hieu ve cam tu van hanh oi su triet*".