Perhaps you should try some spelling variations:
hieu thien » hieu hien, chieu chien, dieu khien
thien cac » hien cac, thien cau, thieu cac
thu sach » tu sach, thuat sach, thuoc sach
cua viet » ca viet, hoa viet, cua vat
ty nang » ky nang, ty hang, ly nang
hanh di » hanh vi, hanh de, hang di
ma hoi » mai hoi, xa hoi, ma hoa
loc va » hoc va, luc va
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: thu sach ((ty nang) or (ty xang)) ma hoi. hieu thien cac ((duc va) or (loc va)) hanh di cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ty nang) OR (ty xang)) ma hoi. hieu thien cac ((duc va) OR (loc va)) hanh di cua viet.
• Adding a wildcard symbol may retrieve word variants: thu sach ((ty nang) or (ty xang)) ma hoi. hieu thien cac ((duc va) or (loc va)) hanh di cua viet*.