Perhaps you should try some spelling variations:
su sach » so sach, vu sach
hanh di » hanh vi, hanh de, hang di
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
ky tang » ky nang, ky dang, kho tang
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
ha hoi » hoa hoi, ha noi, va hoi
tuc va » thuc va, truc va, tuc xa
di cua » dai cua, doi cua, de cua

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 ky tang ((ha hoi) or (xa hoi)). hieu va cam ((tuc va) or (duc va)) hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky tang ((ha hoi) OR (xa hoi)). hieu va cam ((tuc va) OR (duc va)) hanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky tang ((ha hoi) or (xa hoi)). hieu va cam ((tuc va) or (duc va)) hanh di cua tre*.