Perhaps you should try some spelling variations:
cua triet » cua viet, va triet
hieu hieu » hien hieu, hieu hien, thien hieu
su triet » su viet, su tien, ve triet
danh vai » danh sai, danh va, doanh van
luc nuoc » lua nuoc, luan nuoc, duoc nuoc
hieu luc » hieu luat, hieu qua
sach ty » sach y, sach tu, sach thu
va danh » va dinh, va dan, va hanh
nang xa » lang xa, nang ma, mang xa
tu sach » thu sach, su sach, te sach

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 (nang x)) hoi. hieu hieu luc nuoc va danh vai ((cua triet) OR (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (nang x)) hoi. hieu hieu luc nuoc va danh vai ((cua triet) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((nang xa) or (nang x)) hoi. hieu hieu luc nuoc va danh vai ((cua triet) OR (su triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang xa) or (nang x)) hoi. hieu hieu luc nuoc va danh vai ((cua triet) OR (su triet))*.