Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
tang tai » hang tai, dung tai, sang tao
tai khoa » da khoa, noi khoa
te sach » toc sach
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
hieu ve » hieu van
ky tang » ky nang, ky dang, kho tang
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, tuc va, luc va
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (thu sach)) ky tang tai khoa. ((hieu ve) OR (hieu va)) cam xuc va hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (thu sach)) ky tang tai khoa. ((hieu ve) OR (hieu va)) cam xuc va hanh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (thu sach)) ky tang tai khoa. ((hieu ve) OR (hieu va)) cam xuc va hanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (thu sach)) ky tang tai khoa. ((hieu ve) OR (hieu va)) cam xuc va hanh di cua tre*.