Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
danh vai » danh sai, danh va, doanh van
cua viet » ca viet, hoa viet, cua vat
hieu ve » hieu va, hieu van
vai cua » dai cua, hai cua, lai cua
ma hoi » mai hoi, ma hoa, me hoi
y tang » ky tang, 6 tang, 7 tang
luc va » duc va, loc va
tuc va » thuc va, truc va, tuc xa
ve coc » ve cuoc, ve cac, ve co

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach y tang ((ma hoi) OR (xa hoi)). hieu ve coc ((luc va) OR (tuc va)) danh vai cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach y tang ((ma hoi) OR (xa hoi)). hieu ve coc ((luc va) or (tuc va)) danh vai cua viet~".
• Adding a wildcard symbol may retrieve word variants: thuoc sach y tang ((ma hoi) OR (xa hoi)). hieu ve coc ((luc va) or (tuc va)) danh vai cua viet*.