Perhaps you should try some spelling variations:
ban hanh » ban hang
dang xay » dang van, van xay
te sach » toc sach
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
hieu ve » hieu van
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua
cam o » cham o, cam lo, ca o
o ban » co ban, lo ban, do ban

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 ky ((dang xay) or (nang x)) hoi. ((hieu ve) OR (hieu va)) cam o ban hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((dang xay) OR (nang x)) hoi. ((hieu ve) OR (hieu va)) cam o ban hanh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((dang xay) or (nang x)) hoi. ((hieu ve) OR (hieu va)) cam o ban hanh vi cua tre*".