Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cac nuoc » cap nuoc, dat nuoc, cua nuoc
danh vai » danh sai, danh va, doanh van
xang xa » lang xa, mang xa, ang xa
hieu ve » hieu van
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
y xang » ty xang

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