Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hieu van » hieu va, thien van, lieu va
tran van » luan van
trang va » hang va
danh di » danh du, xanh di, danh dien
su sach » so sach, vu sach
so sanh » do sanh
nang xa » nang x, lang xa, nang ma
van cac » van hac, van cau, van bac
y nang » ky nang, ly nang, v nang
di cau » da cau, diem cau

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: ((su sach) OR (so sanh)) y nang xa hoi. hieu van cac ((trang va) OR (tran van)) danh di cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sanh)) y nang xa hoi. hieu van cac ((trang va) OR (tran van)) danh di cau tren~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sanh)) y nang xa hoi. hieu van cac ((trang va) OR (tran van)) danh di cau tren*.