Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
hieu van » thien van, lieu va, hieu ve
sang ma » tang ma, nang ma, sang tao
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
lam duc » lam duoc, pham duc, nam duoc
duc van » duc va, duc tan, duc manh
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky ((nang xa) or (sang ma)) hoi. ((hieu van) OR (hieu va)) lam duc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang xa) OR (sang ma)) hoi. ((hieu van) OR (hieu va)) lam duc van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((nang xa) or (sang ma)) hoi. ((hieu van) OR (hieu va)) lam duc van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang xa) or (sang ma)) hoi. ((hieu van) OR (hieu va)) lam duc van hanh vi cua tre*.