Perhaps you should try some spelling variations:
thanh dao » thanh dat, thanh dam, thanh do
tai khoa » noi khoa
va thanh » gia thanh, ban thanh, va tinh
so sach » so sanh, bo sach, co sach
hieu va » lieu va, hieu qua
dao cua » dai cua, day cua, dan cua
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, sach thu
hieu ve » hieu van
ty nang » ky nang, ty xang, ty hang
luc va » duc va, tuc va, loc va

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 nang ((tai khoa) OR (da khoa)). ((hieu ve) or (hieu va)) coc luc va thanh dao cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty nang ((tai khoa) OR (da khoa)). ((hieu ve) OR (hieu va)) coc luc va thanh dao cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty nang ((tai khoa) OR (da khoa)). ((hieu ve) or (hieu va)) coc luc va thanh dao cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ty nang ((tai khoa) OR (da khoa)). ((hieu ve) or (hieu va)) coc luc va thanh dao cua tre*.