Perhaps you should try some spelling variations:
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
hieu va » hieu qua
cam duc » cam xuc, cao duc, pham duc
va tinh » may tinh
tinh vi » trinh vi, tinh voi, tinh va
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (su sach)) ky nang x hoi. ((hieu va) OR (lieu va)) cam duc va tinh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang x hoi. ((hieu va) OR (lieu va)) cam duc va tinh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky nang x hoi. ((hieu va) OR (lieu va)) cam duc va tinh vi cua tre*".