Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
ban hanh » ban hang
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
duc ban » duc tan, duc van, dua ban
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
ty nang » ky nang, ty xang, ty hang
cam duc » cam xuc, cao duc, pham duc
va cam » va cham, va cac, va cao
hanh d » hanh de, anh d, hanh _
x hoi » xa hoi, o hoi, 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: tu sach ty nang ((x hoi) or (x ho)). hieu va cam duc ban hanh d ((cua tre) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((x hoi) OR (x ho)). hieu va cam duc ban hanh d ((cua tre) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((x hoi) or (x ho)). hieu va cam duc ban hanh d ((cua tre) or (su triet))*.