Perhaps you should try some spelling variations:
hanh dao » lanh dao, thanh dat, thanh dam
so sach » so sanh, bo sach, co sach
dao cua » dai cua, day cua, dan cua
va hanh » van hanh, va thanh, va danh
cam tuc » cam xuc, cam tu, nam thuc
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
lai hoa » dai hoa, loai hoc
ty hang » ly hang, ty xang, thi hang
ty mang » ty xang, tin mang, tri mang
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ((ty mang) OR (ty hang)) lai hoa. ((hieu ve) or (hieu va)) cam tuc va hanh dao cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((ty mang) OR (ty hang)) lai hoa. ((hieu ve) OR (hieu va)) cam tuc va hanh dao cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((ty mang) OR (ty hang)) lai hoa. ((hieu ve) or (hieu va)) cam tuc va hanh dao cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ((ty mang) OR (ty hang)) lai hoa. ((hieu ve) or (hieu va)) cam tuc va hanh dao cua tre*.