Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
sach tru » sach truc, sach thu, sach tu
cham duc » cham soc, pham duy, phan duc
hanh de » hanh ve, hanh kem
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
nang xa » lang xa, nang ma, mang xa
hieu tu » chieu tu, hieu tuc, hien tu
de su » den su, ve su, de 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 tru ((nang xa) or (nang x)) hoi. hieu tu ((cham duc) OR (pham duc)) va hanh de su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tru ((nang xa) OR (nang x)) hoi. hieu tu ((cham duc) OR (pham duc)) va hanh de su triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tru ((nang xa) or (nang x)) hoi. hieu tu ((cham duc) OR (pham duc)) va hanh de su triet*".