Perhaps you should try some spelling variations:
va hanh » van hanh, va thanh, va danh
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
sach ky » sac ky, sach ty, sach kem
cac tac » cac toc, cac bac, cac dac
te cua » tue cua, le cua
de cua » le cua, dieu cua
ve cac » va cac, vien cac
tac va » tac da, tac xa, tuc va

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) OR (sach y)) lang xa hoi. hieu ve cac tac va hanh ((de cua) OR (te cua)) te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sach y)) lang xa hoi. hieu ve cac tac va hanh ((de cua) OR (te cua)) te~".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach y)) lang xa hoi. hieu ve cac tac va hanh ((de cua) OR (te cua)) te*.