Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
nang cai » nang cao, nang tai, nang cap
su sach » vu sach
va hanh » van hanh, va thanh, va danh
va cham » va chat, va tham
ve cham » ve chat, vu cham, ve chim
cai hoi » cau hoi, dai hoi, cai hoa
so sach » so sanh, bo sach, co sach
su tien » su kien, su hien, tu tieng
soc va » hoc va, loc va, doc va
tai su » tai so, tai tu, lai 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 cai hoi. hieu ((ve cham) OR (va cham)) soc va hanh tai su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ky nang cai hoi. hieu ((ve cham) OR (va cham)) soc va hanh tai su tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) ky nang cai hoi. hieu ((ve cham) OR (va cham)) soc va hanh tai su tien".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) ky nang cai hoi. hieu ((ve cham) OR (va cham)) soc va hanh tai su tien*.