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

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang xa) OR (lang ha)) hoi. ((hieu ve) OR (hieu va)) cau duc va hanh vi cuu tre~.
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang xa) or (lang ha)) hoi. ((hieu ve) or (hieu va)) cau duc va hanh vi cuu tre*.