Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
dang xay » dang van, van xay
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
cam tuc » cam xuc, cam tu, nam thuc
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va
nang xa » nang x, lang xa, nang ma
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: tu sach ky ((nang xa) or (dang xay)) hoi. ((hieu ve) or (hieu van)) cam tuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (dang xay)) hoi. ((hieu ve) OR (hieu van)) cam tuc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) or (dang xay)) hoi. ((hieu ve) or (hieu van)) cam tuc va hanh vi cua tre*.