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