Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
pham tai » pham thi, pham van
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
cau duc » cao duc, cau luc, chu duc
duc san » duc tan, duc van, dac san
cuc tu » cuc du, luc tu, duc tu

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 ty ((nang xa) or (lang xa)) hoi. ((hieu van) OR (hieu va)) cau duc san pham tai cuc tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (lang xa)) hoi. ((hieu van) OR (hieu va)) cau duc san pham tai cuc tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((nang xa) or (lang xa)) hoi. ((hieu van) OR (hieu va)) cau duc san pham tai cuc tu".
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang xa) or (lang xa)) hoi. ((hieu van) OR (hieu va)) cau duc san pham tai cuc tu*.