Perhaps you should try some spelling variations:
dieu cua » dieu tra
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
de cua » le cua, te cua
tuc va » thuc va, truc va, tuc xa
sach v » sach va, sach y, sach 2
xac va » tac va, ac va, bac va
ve cac » va cac, vien cac
v nang » va nang, vu nang, van nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach v nang xa hoi. hieu ve cac ((xac va) or (tuc va)) dinh ((de cua) OR (dieu cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach v nang xa hoi. hieu ve cac ((xac va) OR (tuc va)) dinh ((de cua) OR (dieu cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach v nang xa hoi. hieu ve cac ((xac va) or (tuc va)) dinh ((de cua) OR (dieu cua)) te".
• Adding a wildcard symbol may retrieve word variants: su sach v nang xa hoi. hieu ve cac ((xac va) or (tuc va)) dinh ((de cua) OR (dieu cua)) te*.