Perhaps you should try some spelling variations:
dau treo » dau tren, cau treo, dau theo
doanh va » doan va, doanh tai, doanh cua
thu sach » tu sach, thuat sach, thuoc sach
thu nang » thi nang, thu hang, thu bang
duy van » dung van
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
va dau » va dao
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (thu sach)) thu nang x hoi. hieu ve pham ((duy van) OR (duy vat)) doanh va dau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (thu sach)) thu nang x hoi. hieu ve pham ((duy van) OR (duy vat)) doanh va dau treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (thu sach)) thu nang x hoi. hieu ve pham ((duy van) OR (duy vat)) doanh va dau treo".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (thu sach)) thu nang x hoi. hieu ve pham ((duy van) OR (duy vat)) doanh va dau treo*.