Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
nang tai » hang tai, tang tai, nang cao
sang tai » hang tai, sang tao, tang tai
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
cam tuc » cam xuc, cam tu, nam thuc
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, truc va, tuc xa
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: so sach ky ((nang tai) OR (sang tai)) khoa. ((hieu van) or (hieu va)) cam tuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky ((nang tai) OR (sang tai)) khoa. ((hieu van) OR (hieu va)) cam tuc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky ((nang tai) OR (sang tai)) khoa. ((hieu van) or (hieu va)) cam tuc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ky ((nang tai) OR (sang tai)) khoa. ((hieu van) or (hieu va)) cam tuc va hanh vi cua tre*.