Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
su triet » su viet, su tien, ve triet
lang xa » lang ha, dang xay, lang van
tu lang » cu lang, tu lanh, xu lang
hieu va » lieu va
sach tu » sach thu, cach tu, sach ty
cac toc » cac toi, cac nuoc, cac thoi
hanh di » hanh de, hang di, danh di
toc va » hoc va, toc ta, tuc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach tu lang xa hoi. ((hieu va) OR (hieu qua)) cac toc va ((hanh di) or (hanh vi)) su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach tu lang xa hoi. ((hieu va) OR (hieu qua)) cac toc va ((hanh di) OR (hanh vi)) su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach tu lang xa hoi. ((hieu va) OR (hieu qua)) cac toc va ((hanh di) or (hanh vi)) su triet".
• Adding a wildcard symbol may retrieve word variants: thuat sach tu lang xa hoi. ((hieu va) OR (hieu qua)) cac toc va ((hanh di) or (hanh vi)) su triet*.