Perhaps you should try some spelling variations:
dieu cua » dieu tra
su sach » so sach
vu sach » vu bach, vu khach
truc va » thuc va, thuc vat, trung va
cao hoi » cau hoi, co hoi, cao hoc
hieu ve » hieu va, hieu van
ve cac » va cac, vien cac
tuc va » thuc va, tuc xa, duc va
v nang » va nang, vu nang, van nang
cua te » cua tu

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 (vu sach)) v nang cao hoi. hieu ve cac ((tuc va) OR (truc va)) dang dieu cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu sach)) v nang cao hoi. hieu ve cac ((tuc va) OR (truc va)) dang dieu cua te~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) v nang cao hoi. hieu ve cac ((tuc va) OR (truc va)) dang dieu cua te*.