Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
cham duc » cham soc, pham duy, phan duc
hau treo » cau treo, cau theo, dau tren
tu sach » thu sach, su sach, te sach
nang xa » lang xa, nang ma, mang xa
hieu ve » hieu va, hieu van
va luan » vay luan, van luan, va quan
van hau » van ha, van hai, van dau

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

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