Perhaps you should try some spelling variations:
hoc dung » hoc ung, hoc dan, tac dung
hoc duoc » hoc nuoc, hoa duoc
vu sach » vu bach, su sach, vu khach
tinh di » tinh doi, trinh di, tinh da
va tinh » may tinh
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2
me hoi » le hoi
v nang » va nang, vu nang, van nang
di cua » dai cua, doi cua, de cua

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: vu sach v nang ((me hoi) OR (ma hoa)). hieu ve ((hoc duoc) OR (hoc dung)) va tinh di cua tre~.
• Adding a wildcard symbol may retrieve word variants: vu sach v nang ((me hoi) or (ma hoa)). hieu ve ((hoc duoc) or (hoc dung)) va tinh di cua tre*.