Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
dang xay » dang van, van xay
va hanh » van hanh, va thanh, va danh
sach ky » sac ky, sach y, sach ty
su sach » so sach, vu sach
lang ha » long ha
cua tre » cua te, cuu tre, cua triet
lam lo » lam co, cam lo, lam so
nam lo » nam bo, nam so, nam co
vi cua » vai cua, di cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((lang ha) OR (dang xay)) hoi. hieu van ((lam lo) OR (nam lo)) va hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((lang ha) or (dang xay)) hoi. hieu van ((lam lo) OR (nam lo)) va hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((lang ha) or (dang xay)) hoi. hieu van ((lam lo) OR (nam lo)) va hanh vi cua tre*.