Perhaps you should try some spelling variations:
dung hai » dung tai, dung ha, dung sai
te sach » toc sach
nang xa » nang x, lang xa, nang ma
long ha » dong ha, cong ha, dong hoa
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
va dung » van dung, va duong, vat dung
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y ((nang xa) or (((lang ha) OR (long ha)))) hoi. hieu va cac duc va dung hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y ((nang xa) OR (((lang ha) OR (long ha)))) hoi. hieu va cac duc va dung hai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y ((nang xa) or (((lang ha) OR (long ha)))) hoi. hieu va cac duc va dung hai cua tre*".