Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
van bac » van ban, van bao, van hac
bac tap » bai tap, ba tap, bac tai
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, lai cua
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
vi 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: te sac ky ((nang xa) OR (lang xa)) hoi. hieu van bac tap va hanh ((vi cua) OR (vai cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky ((nang xa) or (lang xa)) hoi. hieu van bac tap va hanh ((vi cua) OR (vai cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: te sac ky ((nang xa) or (lang xa)) hoi. hieu van bac tap va hanh ((vi cua) OR (vai cua)) tre*.