Perhaps you should try some spelling variations:
hieu quan » lieu quan, thien quan, lien quan
hoc sach » hoc sinh, hoc cac, hoc anh
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
cam luc » cam xuc, cau luc
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
va cua » va chua, via cua, ca cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach v nang xa hoi. ((hieu qua) or (hieu quan)) cam luc ((va hanh) OR (va danh)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach v nang xa hoi. ((hieu qua) OR (hieu quan)) cam luc ((va hanh) OR (va danh)) va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach v nang xa hoi. ((hieu qua) or (hieu quan)) cam luc ((va hanh) OR (va danh)) va cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach v nang xa hoi. ((hieu qua) or (hieu quan)) cam luc ((va hanh) OR (va danh)) va cua tre*.