Perhaps you should try some spelling variations:
cam truc » cau truc, nam truc, lam truoc
ban hanh » ban hang
truc ban » thuc ban, truc dan, truc van
su sach » so sach, vu sach
vai cua » dai cua, hai cua, lai cua
hieu va » lieu va, hieu qua
hieu ve » hieu van
nang xa » nang x, lang xa, nang ma
sach v » sach va, sach y, sach 2
vi cua » di cua
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) or (hieu va)) cam truc ban hanh ((vi cua) OR (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach v nang xa hoi. ((hieu ve) OR (hieu va)) cam truc ban hanh ((vi cua) OR (vai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach v nang xa hoi. ((hieu ve) or (hieu va)) cam truc ban hanh ((vi cua) OR (vai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: su sach v nang xa hoi. ((hieu ve) or (hieu va)) cam truc ban hanh ((vi cua) OR (vai cua)) tre*.