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

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) OR (thuat sach)) y tang ((ma hoi) OR (xa hoi)). hieu ve coc luc va danh vai cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuoc sach) or (thuat sach)) y tang ((ma hoi) OR (xa hoi)). hieu ve coc luc va danh vai cua viet~".
• Adding a wildcard symbol may retrieve word variants: ((thuoc sach) or (thuat sach)) y tang ((ma hoi) OR (xa hoi)). hieu ve coc luc va danh vai cua viet*.