Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien dai » hien dai
sach ty » sach y, sach tu, sach thu
vai cua » dai cua, hai cua, lai cua
vu sach » vu bach, su sach, vu khach
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
tac va » tac da, tac xa, tac ha
tuc va » thuc va, truc va, tuc xa
vi cua » di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ty nang xa hoi. hieu vien dai ((tac va) OR (tuc va)) thanh ((vi cua) or (vai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty nang xa hoi. hieu vien dai ((tac va) OR (tuc va)) thanh ((vi cua) OR (vai cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ty nang xa hoi. hieu vien dai ((tac va) OR (tuc va)) thanh ((vi cua) or (vai cua)) triet".
• Adding a wildcard symbol may retrieve word variants: vu sach ty nang xa hoi. hieu vien dai ((tac va) OR (tuc va)) thanh ((vi cua) or (vai cua)) triet*.