Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, va danh
cau luc » cau truc, cau phuc
hieu va » lieu va, hieu qua
hieu ve » hieu van
cuu tre » cua tre, cau tren, cau treo
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
luc va » duc va, tuc va, loc va
vi cuu » vi luu, vinh cuu

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 y ((nang xa) OR (lang xa)) hoi. ((hieu ve) or (hieu va)) cau luc va hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang xa) OR (lang xa)) hoi. ((hieu ve) OR (hieu va)) cau luc va hanh vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((nang xa) OR (lang xa)) hoi. ((hieu ve) or (hieu va)) cau luc va hanh vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang xa) OR (lang xa)) hoi. ((hieu ve) or (hieu va)) cau luc va hanh vi cuu tre*.