Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
te sach » toc sach
vai cua » dai cua, hai cua, lai cua
va dinh » van dinh, va kinh, va tinh
cac dac » cac dan, cac dai, cac bac
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
dac va » duc va, day va, dat va
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 sach ty nang xa hoi. ((hieu ve) OR (hieu van)) cac dac va dinh ((vi cua) OR (vai cua)) te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty nang xa hoi. ((hieu ve) or (hieu van)) cac dac va dinh ((vi cua) OR (vai cua)) te~".
• Adding a wildcard symbol may retrieve word variants: te sach ty nang xa hoi. ((hieu ve) or (hieu van)) cac dac va dinh ((vi cua) OR (vai cua)) te*.