Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
dinh va » dinh van, dinh ve, tinh va
va dinh » van dinh, va kinh, va tinh
tu nong » tu dong, tu cong, tu tong
tu nang » tru nang, tu nano, tu lang
va cao » va co, va dao, va bao
va cua » va chua, via cua, ca cua
cua te » cua tu

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 ((tu nang) or (tu nong)) xa hoi. hieu ((va cao) OR (va cac)) duc va dinh va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((tu nang) OR (tu nong)) xa hoi. hieu ((va cao) OR (va cac)) duc va dinh va cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((tu nang) or (tu nong)) xa hoi. hieu ((va cao) OR (va cac)) duc va dinh va cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach ((tu nang) or (tu nong)) xa hoi. hieu ((va cao) OR (va cac)) duc va dinh va cua te*.